Poly(arylene thioether) block copolymer and production process thereof

ABSTRACT

Disclosed herein are a poly(arylene thioether) block copolymer alternately comprising (A) at least one poly(arylene thioether-ketone) block having predominant recurring units of the formula ##STR1## wherein the --CO-- and --S-- are in the para position to each other and (B) at least one poly(arylene thioether) block having predominant recurring units of the formula ##STR2## (a) the ratio of the total amount of the poly(arylene thioether) block (B) to the total amount of the poly(arylene thioether-ketone) block (A) being within a range of 0.05-5 by weight, (b) the average polymerization degree of the poly(arylene thioether) block (B) being at least 10, and (c) said block copolymer having a melt viscosity of 2-100,000 poises as measured at 350° C. and a shear rate of 1,200/sec as well as a production process the poly(arylene thioether) block copolymer. The invention also provides a stabilized poly(arylene thioether) block copolymer containing a basic compound either alone or in combination with an antioxidant.

This application is a divisional application of application Ser. No.07/424,624, filed Oct. 20, 1989 now U.S. Pat. No. 5,120,808.

FIELD OF THE INVENTION

This invention relates to crystalline poly(arylene thioether) blockcopolymers having excellent melt stability, processability and handlingproperties, and more specifically to novel block copolymers containingat least one poly(arylene thioether-ketone) block having predominantrecurring units of the formula ##STR3## and at least one poly(arylenethioether) block having predominant recurring units of the formula##STR4## and also to a process for the production thereof.

This invention is also concerned with products formed or molded from theblock copolymers. In addition, this invention also pertains tostabilized derivatives of the block copolymers.

BACKGROUND OF THE INVENTION

In the fields of the electronic and electrical industry and theautomobile, aircraft and space industries, there is a strong demand inrecent years for crystalline thermoplastic resins having high heatresistance of about 300° C. or higher in terms of melting point andmoreover easy melt processability.

Recently, poly(arylene thioether-ketones) (hereinafter abbreviated as"PTKs") have drawn attention for their high melting points. Variousstudies are now under way thereon.

There are some disclosure on PTKs, for example, in Japanese PatentLaid-Open No. 58435/1985, German Offenlegungsschrift 34 05 523 A1,Japanese Patent Laid-Open No. 104126/1985, Japanese Patent Laid-Open No.13347/1972, Indian J. Chem., 21A, 501-502 (May, 1982), Japanese PatentLaid-Open No. 221229/1986, U.S. Pat. Nos. 4,716,212, 4,690,972, EuropeanPatent Publication No. 0,270,955 A2, European Patent Publication No.0,274,754 A2, European Patent Publication No. 0,280,325 A2, etc.

Regarding the PTKs described in the above publications, neither moldingnor forming has however succeeded to date in accordance withconventional melt processing techniques. Incidentally, the term"conventional melt processing techniques" as used herein means usualmelt processing techniques for thermoplastic resins, such as extrusion,injection molding and melt spinning.

The unsuccessful molding or forming of PTKs by conventional meltprocessing techniques is believed to be attributed to the poor meltstability of the prior art PTKs, which tended to lose theircrystallinity or to undergo crosslinking and/or carbonization, resultingin a rapid increase in melt viscosity, upon their melt processing.

The present inventors thus conducted an investigation with a view towarddeveloping a process for economically producing PTKs having meltstability sufficient to permit the application of conventional meltprocessing techniques. The investigation led to the successful provisionof PTKs having significantly improved heat stability upon melting(hereinafter called "melt stability") (Japanese Patent Laid-Open No.54031/1989).

It has also found that the melt stability of the melt-stable PTKs uponmelt processing can be improved further by the addition of a basiccompound such as the hydroxide or oxide of a Group IA or Group IIA metalof the periodic table to them (Japanese Patent Application No.142772/1988).

The melt-stable PTKs obtained as described above have a high meltingpoint, typified by the extremely high melting point of the homopolymerwhich reaches as high as about 360° C. This is however not all good.Their melt processing temperatures are high accordingly, so that meltprocessing facilities for high-temperature processing are required.Further, a stringent temperature control is required to perform meltprocessing without deterioration by heat.

The melt-stable PTKS are generally obtained as fine powders having aparticle size of approximately 5-20 μm. This has led to an additionalproblem upon their production such that they show poor handlingproperties in their collection step after polymerization, especially infiltration, washing, drying and transportation. Still further problemshave also arisen such as poor metering property upon melt processing andoccurrence of blocking in hoppers or the like.

OBJECTS AND SUMMARY OF THE INVENTION

An object of this invention is to provide polymers with improvedprocessability and handling properties while retaining the excellentproperties, such as heat resistance and crystallinity, of theaforementioned melt-stable PTKs as much as possible.

With a view toward improving the processability of a melt-stable PTK,the present inventors first of all attempted to lower the melting point,i.e., processing temperature of the melt-stable PTK by randomcopolymerization of its monomer with monomers of a kind different fromthe first-mentioned monomer. Namely, 4,4'-dihalobenzophenone as adihalogenated aromatic compound wa combined with dihalobenzenes asdihalogenated aromatic compounds of a kind different from4,4'-dihalobenzophenone, respectively, followed by randomcopolymerization. However, the resultant random copolymers tended tohave lower crystallinity and heat resistance and poorer melt stabilityas the proportions of the dihalobenzenes increased.

Further, dihalogenated benzophenones represented by4,4'-dihalobenzophenones have been activated by the ketone group andhave far higher reactivity compared to dihalobenzenes. They hence haveextremely poor copolymerizability with dihalobenzenes.

The present inventors then attempted to produce a PTK-PATE blockcopolymer in which a poly(arylene thioether) (hereinafter abbreviated as"PATE") having recurring units of the formula ##STR5## is incorporatedas blocks in the chain of a melt-stable PTK. As a result, it has beenfound that a poly(arylene thioether) block copolymer having excellentprocessability and high crystallinity can be obtained by using as aprepolymer a PATE, which has a particular average polymerization degreeand contains terminal thiolate groups and/or thiol groups as reactiveterminal groups, and reacting the PATE prepolymer with a4,4'-dihalobenzophenone and an alkali metal sulfide under specificconditions in an organic amide solvent.

It has also been found that a block copolymer having excellentproperties can be obtained by reacting a PATE prepolymer with a PTKprepolymer.

It has also been uncovered that each of these block copolymer can beobtained as granules having good handling properties from itspolymerization systems by a conventional collection method.

It has also been revealed that each of the block copolymers has highmelt stability and various formed or molded products can be easilyobtained from the block copolymer alone or its compositions.

It has also been found that a block copolymer of improved resistance tothe reduction of melt stability and crystallinity can be obtained byadding a specific basic compound, optionally along with an antioxidant,to each of the above block copolymer.

The present invention has been brought to completion on the basis ofthese findings.

In one aspect of this invention, there is thus provided a poly(arylenethioether) block copolymer alternately comprising (A) at least onepoly(arylene thioether-ketone) block having predominant recurring unitsof the formula ##STR6## wherein the --CO-- and --S-- are in positioneach other and (B) at least one poly(arylene thioether) block havingpredominant recurring units of the formula ##STR7## (a) the ratio of thetotal amount of the poly(arylene thioether) block (B) to the totalamount of the poly(arylene thioether-ketone) block (A) ranging from 0.05to 5 by weight,

(b) the average polymerization degree of the poly(arylene thioether)block (B) being at least 10, and

(c) said block copolymer having a melt viscosity of 2-100,000 poises asmeasured at 350° C. and a shear rate of 1,200/sec.

In another aspect of this invention, there is also provided a processfor the production of a poly(arylene thioether) block copolymercomprising (A) at least one poly(arylene thioether-ketone) block and (B)at least one poly(arylene thioether) block, which comprises at least thefollowing two steps:

i) heating in the presence of water an organic amide solvent containinga dihalogenated aromatic compound, which consists principally of adihalobenzene, and an alkali metal sulfide, whereby a reaction mixturecontaining a poly(arylene thioether) prepolymer having predominantrecurring units of the formula ##STR8## and reactive terminal groups isformed, and ii) mixing the reaction mixture, which has been obtained inthe step i), with a dihalogenated aromatic compound consistingprincipally of at least one dihalobenzophenone selected from4,4'-dichlorobenzophenone and 4,4'-dibromobenzophenone, an alkali metalsulfide, an organic amide solvent and water and heating the resultantmixture to form a poly(arylene thioether-ketone) block havingpredominant recurring units of the formula ##STR9## wherein the --CO--and --S-- are in the para position to each other; said first and secondsteps i) and ii) being conducted under the following conditions (a)-(f):

(a) in the first step i), the ratio of the water content to the amountof the charged organic amide solvent being 0.2-5 (mol/kg), the ratio ofthe amount of the charged dihalogenated aromatic compound to the amountof the charged alkali metal sulfide being 0.8-1.05 (mol/mol), and thepolymerization being conducted until the average polymerization degreeof the poly(arylene thioether) prepolymer becomes at least 10,

(b) in the second step, the ratio of the water content to the amount ofthe charged organic amide solvent being controlled within a range of2.5-15 (mol/kg),

(c) in the second step, the ratio of the total amount of the chargeddihalogenated aromatic compound, said total amount being the amount ofthe whole dihalogenated aromatic compounds including the dihalobenzeneand the dihalobenzophenone to the total amount of the charged alkalimetal sulfide, said latter total amount being the total amount of thealkali metal sulfide charged in the first step i) and that charged inthe second step ii), being controlled within a range of 0.95-1.2(mol/mol),

(d) the ratio of the charged amount of the dihalogenated aromaticcompound consisting principally of the dihalobenzophenone to the chargedamount of the dihalogenated aromatic compound consisting principally ofthe dihalobenzene being controlled within a range of 0.1-10 (mol/mol),

(e) the reaction of the second step ii) being conducted within atemperature range of 150°-300° C. with the proviso that the reactiontime at 210° C. and higher is not longer than 10 hours, and

(f) in the second step ii), the reaction is conducted until the meltviscosity of the resulting block copolymer becomes 2-100,000 poises asmeasured at 350° C. and a shear rate of 1,200/sec.

In a further aspect of this invention, there is also provided a processfor the production of a poly(arylene thioether) block copolymercomprising (A) at least one poly(arylene thioether-ketone) block and (B)at least one poly(arylene thioether) block, which comprises at least thefollowing three steps:

i) heating in the presence of water an organic amide solvent containinga dihalogenated aromatic compound, which consists principally of adihalobenzene, and an alkali metal sulfide, whereby a first reactionmixture containing a poly(arylene thioether) prepolymer havingpredominant recurring units of the formula ##STR10## and reactiveterminal groups is formed, ii) heating in the presence of water anorganic amide solvent containing a dihalogenated aromatic compound,which consists principally of at least one dihalobenzophenone selectedfrom 4,4'-dichlorobenzophenone and 4,4'-dibromobenzophenone, an alkalimetal sulfide, whereby a second reaction mixture containing apoly(arylene thioether-ketone) prepolymer having predominant recurringunits of the formula ##STR11## wherein the --CO-- and --S-- are in thepara position to each other and reactive terminal groups is formed, and

iii) mixing and reacting the first reaction mixture, which has beenobtained in the first step i) and contains the poly(arylene thioether)prepolymer, with the second reaction mixture obtained in the second stepii) and containing the poly(arylene thioetherketone) prepolymer;

said first through third steps i)-iii) being conducted under thefollowing conditions (a)-(g):

(a) in the first step i), the ratio of the water content to the amountof the charged organic amide solvent being 0.2-5 (mol/kg), the ratio ofthe amount of the charged dihalogenated aromatic compound to the amountof the charged alkali metal sulfide being 0.8-1.05 (mol/mol), and thepolymerization being conducted until the average polymerization degreeof the poly(arylene thioether) prepolymer becomes at least 10,

(b) in the second step, the ratio of the water content to the amount ofthe charged organic amide solvent being controlled within a range of2.5-15 (mol/kg) and the reaction being conducted within a temperaturerange of 60°-300° C. with the proviso that the reaction time at 210° C.and higher is not longer than 10 hours,

(c) in the third step, the ratio of the water content to the amount ofthe charged organic amide solvent being controlled within a range of2.5-15 (mol/kg)

(d) in the third step, the ratio of the total amount of the chargeddihalogenated aromatic compound, said total amount being the amount ofthe whole dihalogenated aromatic compounds including the dihalobenzeneand the dihalobenzophenone to the total amount of the charged alkalimetal sulfide, said latter total amount being the total amount of thealkali metal sulfide charged in the first step i) and that charged inthe second step ii), being controlled within a range of 0.95-1.2(mol/mol),

(e) the ratio of the whole poly(arylene thioether) prepolymer to thewhole poly(arylene thioether-ketone) prepolymer being controlled at0.05-5 by weight,

(f) the reaction of the third step iii) being conducted within atemperature range of 150°-300° C. with the proviso that the reactiontime at 210° C. and higher is not longer than 10 hours, and

(g) in the third step iii), the reaction is conducted until the meltviscosity of the resulting block copolymer becomes 2-100,000 poises asmeasured at 350° C. and a shear rate of 1,200/sec.

In a still further aspect of this invention, there is also provided aformed or molded product of the above-described poly(arylene thioether)block copolymer.

In a still further aspect of this invention, there is also provided astabilized poly(arylene thioether) block copolymer comprising thepoly(arylene thioether) block copolymer and per 100 parts by weight ofthe above poly(arylene thioether) block copolymer, 0.1-30 parts byweight of at least one basic compound selected from the group consistingof hydroxides, oxides and aromatic carboxylates of group IIA metals ofthe periodic table other than magnesium, and aromatic carboxylates,carbonates, hydroxides, phosphates, including condensation products, andborates, including condensation products, of group IA metals of theperiodic table and 0-10 parts by weight of at least one antioxidantselected from the group consisting of hindered phenolic compounds,phosphorus compounds and hindered amine compounds.

In a still further aspect of this invention, there is also provided aformed or molded product of the above-described stabilized poly(arylenethioether) block copolymer.

DETAILED DESCRIPTION OF THE INVENTION

Features of the present invention will hereinafter be described indetail.

Poly(Arylene Thioether) Block Copolymers Chemical structure of blockcopolymers

The poly(arylene thioether) block copolymers according to the presentinvention are block copolymers alternately comprising (A) at least onePTK block having predominant recurring units of the formula ##STR12##wherein the --CO-- and --S-- are in the para position to each other and(B) at least one PATE block having predominant recurring units of theformula ##STR13##

The block copolymer of the present invention can have a desiredstructure containing both blocks in an alternate order, such as(A)-(B)-(A)]_(m) (B)-(A), m being 0 or an integer of 1 or greater or(A)-(B)-(A)]_(n) (B), n being 0 or an integer of 1 or greater.

It is however required that the weight ratio of the total amount ofblocks (B) to the total amount of blocks (A) be within a range of0.05-5, preferably 0.1-4, more preferably 0.15-3.

The block (A) serves to impart high degrees of heat resistance andcrystallinity to the block copolymer. On the other hand, the block (B)contributes to the reduction of the processing temperature and thegranulation while maintaining the high crystallinity. Therefore, blockcopolymers in each of which the weight ratio of the total amount ofblocks (B) to the total amount of blocks (A) is at least 0.05 butsmaller than 1, preferably at least 0.1 but smaller than 1 featureparticularly good heat resistance and high crystallinity. Ratios in arange of 1-5, preferably 1-4 give block copolymers excellent especiallyin processability while retaining excellent crystallinity. However, anyweight ratios of the total amount of blocks (B) to the total amount ofblocks (A) smaller than 0.05 are too small to achieve any sufficientreduction in processing temperature or the formation into granules. Tothe contrary, any ratios greater than 5 lead to a substantial reductionin heat resistance and disturb the balancing between heat resistance andprocessability. Ratios outside the above range are therefore notpreferred.

It is essential for the block (B) to have an average polymerizationdegree of at least 10, preferably 20 or higher.

If the average polymerization degree of the block (B) is smaller than10, the resulting block copolymer becomes similar to a random copolymerso that physical properties such as crystallinity, heat resistance andmelt stability are all reduced substantially. Such small averagepolymerization degrees are therefore not preferred. In addition, anyunduly small average polymerization degree of the block (B) leads toanother problem that a block copolymer of high molecular weight canhardly be obtained.

The block (A) and block (B) can contain one or more recurring unitsother than their predominant recurring units of the formulae ##STR14##and ##STR15## to an extent that the objects of this invention are notimpaired.

Exemplary recurring units other than the above recurring units mayinclude: ##STR16##

In general, these other recurring units can be introduced into the blockcopolymers by using the corresponding various dihalogenated aromaticcompounds as comonomers.

Physical Properties of the Block Copolymers

Physical properties and other characteristics of the poly(arylenethioether) block copolymers according to this invention will next bedescribed in detail from the viewpoint of processability, meltstability, crystallinity and the like.

(1) Processability

The melting point of PTK homopolymer is about 360° C. The extent of areduction in the melting point due to copolymerization with anothermonomer of a different kind, ΔTm=[360° C.-Tm (melting point ofcopolymer)] is generally proportional to the extent of a reduction inthe melt processing temperature. Accordingly, ΔTm can be used as anindex indicative of processing temperature reducing effect, namely,processability improving effect.

ΔTm may preferably be 10°-80° C., more preferably 20°-70° C., mostpreferably 30°-60° C. If ΔTm is lower than 10° C., there is a potentialproblem that the processability improving effect may not be sufficient.If ΔTm is higher than 80° C., there is another potential problem thatthe block copolymer may lose the characteristics as a heat-resistantresin. ΔTm outside the above range is therefore not preferred.

(2) Crystallinity

One of great features of the block copolymers according to thisinvention resides in that they have not only excellent processabilitybut also high crystallinity. Crystallinity imparts high heat resistanceto a copolymer. To have a block copolymer equipped with high heatresistance, it is essential that the block copolymer has sufficientcrystallinity.

In general, melt crystallization enthalpy ΔHmc is proportional to thedegree of crystallization when a molten polymer undergoescrystallization. On the other hand, melt crystallization temperature Tmcserves as an index of the readiness of crystallization. Therefore, themelt crystallization enthalpy ΔHmc (400° C.) and melt crystallizationtemperature Tmc (400° C.) of a block copolymer according to thisinvention as measured when cooled at a rate of 10° C./min immediatelyafter being heated to 400° C. in an inert gas atmosphere by means of adifferential scanning calorimeter (hereinafter abbreviated as "DSC") canbe used as indices of the crystallinity of the block copolymer.

In addition, residual melt crystallization enthalphy, ΔHmc (400° C./10min) and melt crystallization temperature, Tmc (400° C./10 min)measurable upon determination of the residual crystallinity, both ofwhich will be described subsequently, can be used as an index of notonly melt stability but also crystallinity.

The block copolymers of this invention may have a melt crystallizationenthalpy, ΔHmc (400° C.) of at least 15 J/g, preferably at least 20 J/g,and more preferably at least 25 J/g. On the other hand, Tmc (400° C.)may desirably be at least 180° C., with at least 200° C. being morepreferred. Block copolymers having ΔHmc (400° C.) smaller than 15 J/g orTmc (400° C.) lower than 180° C. may have insufficient heat resistanceas heat resistant polymers and are hence not preferred.

(3) Melt Stability

The greatest feature of the block copolymers according to this inventionresides in that they have melt stability sufficient to permit theapplication of conventional melt processing techniques.

Polymers of poor melt stability tend to lose their crystallinity or toundergo crosslinking or carbonization, resulting in a rapid increase inmelt viscosity, upon melt processing.

It is hence possible to obtain an index of the melt processability of apolymer by investigating the residual crystallinity of the polymer afterholding it at an elevated temperature of its melt processing temperatureor higher for a predetermined period of time. The residual crystallinitycan be evaluated quantitatively by measuring the melt crystallizationenthalpy of the polymer by a DSC.

Specifically, it is possible to use as indices of the melt stability ofa block copolymer its residual melt crystallization enthalphy, ΔHmc(400° C./10 min) and melt crystallization temperature, Tmc (400° C./10min), which are determined at a cooling rate of 10° C./min after theblock copolymer is held at 50° C. for 5 minutes in an inert gasatmosphere, heated to 400° C. at a rate of 75° C./min and then held for10 minutes at 400° C. which is higher than the melt processingtemperature of the block copolymer.

In the case of a copolymer having poor melt stability, it undergoescrosslinking or the like under the above conditions, namely, when it isheld for 10 minutes at the high temperature of 400° C., whereby thecopolymer loses its crystallinity substantially.

The block copolymers of this invention are polymers having the physicalproperties that their residual melt crystallization enthalpies, ΔHmc(400° C./10 min) are at least 10 J/g, more preferably at least 15 J/g,most preferably at least 20 J/g and their melt crystallizationtemperatures, Tmc (400° C./10 min) are at least 170° C., more preferablyat least 180° C., most preferably at least 190° C.

A block copolymer, whose ΔHmc (400° C./10 min) is smaller than 10 J/g orwhose Tmc (400° C./10 min) is lower than 170° C., tends to lose itscrystallinity or to induce a melt viscosity increase upon meltprocessing, so that difficulties are encountered upon application ofconventional melt processing techniques.

Further, the ratio of melt crystallization enthalpy to residual meltcrystallization enthalpy, namely, ΔHmc (400° C.)/ΔHmc (400° C./10 min)can also be used as an index of melt stability. Deterioration by heatbecomes smaller as this ratio decreases. Therefore, it is preferablethat ΔHmc (400° C.10 min) is at least 10 J/g and the above ratio is 5 orsmaller, more preferably 3 or smaller.

(4) Melt Viscosity

In this invention, the melt viscosity η* of each copolymer is used as anindex of its molecular weight.

Specifically, a polymer sample is filled in a Capirograph manufacturedby Toyo Seiki Seisaku-Sho, Ltd. and equipped with a nozzle having aninner diameter of 1 mm and an L/D ratio of 10/1 and is preheated at 350°C. for 5 minutes. Its melt viscosity η* is measured at a shear rate of1,200/sec.

The block copolymers of the present invention have a melt viscosity η*of 2-100,000 poises, preferably 5-50,000 poises, more preferably10-30,000 poises.

Those having a melt viscosity η* lower than 2 poises have an undulysmall molecular weight so that their flowability is too high to applyconventional melt processing techniques. Even if melt-formed ormelt-molded products are obtained, their physical properties areconsiderably inferior. Such low melt viscosities are therefore notpreferred. On the other hand, those having a melt viscosity η* higherthan 100,000 poises have an unduly large molecular weight so that theirflowability is too low to apply conventional melt processing techniques.Such high melt viscosities are therefore not preferred either.

Production Process of Block Copolymers

A variety of processes may be contemplated for the production of theblock copolymers, for example, including:

(1) A dihalogenated aromatic compound consisting principally of a4,4'-dihalobenzophenone and an alkali metal sulfide are added to andreacted with a PATE block (B) which has been prepared in advance,whereby a PTK block (A) is formed.

(2) A dihalogenated aromatic compound consisting principally of adihalobenzene and an alkali metal sulfide are added to and reacted witha PTK block (A) which has been prepared in advance, whereby a PATE block(B) is formed.

(3) PTK block (A) and PATE block (B), which have been preparedseparately, are chemically combined together.

The present inventors carefully studied those processes. As a result, ithas been found that the processes (1) and (3) are suitable for obtainingthe block copolymers of this invention.

A. Raw Materials for Block Copolymers

In the process for the production of a block copolymer of thisinvention, an alkali metal sulfide and a dihalogenated aromatic compoundemployed as principal raw materials for the polymer and an organic amidesolvent and water, including water of hydration, as reactionpolymerization media.

(1) Alkali Metal Sulfide

Illustrative examples of the alkali metal sulfide useful in the practiceof this invention include lithium sulfide, sodium sulfide, potassiumsulfide, rubidium sulfide, cesium sulfide and mixtures thereof.

These alkali metal sulfides may be used as a hydrate or aqueous mixtureor in an anhydrous form. Especially, alkali metal sulfides in the formof a hydrate or aqueous mixture having a water content within the rangespecified in the present invention are advantageous in that adehydration step prior to the polymerization step can be omitted.

Among these alkali metal sulfides, sodium sulfide is industriallypreferred for its low price. An alkali metal sulfide which may be formedin situ in the reaction system can also be used.

From the viewpoint of an industrial raw material containing minimizedimpurities, crystalline sodium sulfide pentahydrate availablecommercially on the market can be used preferably.

(2) Dihalogenated Aromatic Compound

The dihalogenated aromatic compound employed in the present inventionfor the formation of the PTK block (A), including a PTK prepolymer,consists principally of one or more dihalobenzophenones, i.e.,4,4'-dichlorobenzophenone and/or 4,4'-dibromobenzophenone.

The dihalogenated aromatic compound used for the formation of the PATEblock (B), including a PATE prepolymer, consists principally of adihalobenzene such as p-dichlorobenzene or m-dichlorobenzene.

As other copolymerizable dihalogenated aromatic compounds, may bementioned, for example, dihalobenzophenones other than 4,4'-isomers,dihaloalkylbenzenes, dihalobiphenyls, dihalodiphenyl suIfones,dihalonaphthalenes, bis(halogenated phenyl)methanes, dihalopyridines,dihalothiophenes and dihalobezonitriles, and mixtures thereof. Assubstituent halogen atoms, chlorine or bromine atoms may be usedpreferably from the economical viewpoint. Within a range not giving toomuch effects to the cost, a small amount of a fluorine compound, forexample, difluorobenzophenone or the like may also be used incombination.

It is also permissible to produce a block copolymer, which has apartially crosslinked and/or branched structure, by causing atrihalogenated or higher polyhalogenated compound to exist in a reactionsystem in such a small amount that the processability and physicalproperties of the copolymer may not be impaired to any substantialextent. As illustrative examples of the trihalogenated or higherpolyhalogenated compound usable for the above purpose, may be mentionedbis(dichlorobenzoyl)benzene, bis(dibromobenzoyl)benzene,trichlorobenzophenone, tribromobenzophenone, tetrachlorobenzophenone,tetrabromobenzophenone, trichlorobenzene, tribromobenzene,tetrachlorobenzene and the like, and mixtures thereof.

(3) Organic Amide Solvent

As reaction media useful for the production process of the blockcopolymers according to this invention, aprotic polar organic solventshaving excellent heat stability and alkali resistance can be used. Ofthese, organic amide solvents, including carbamic amides, are preferred.

As such organic amide solvents, may be mentioned N-methylpyrrolidone,N-ethylpyrrolidone, hexamethylphosphoric triamide, tetramethylurea,dimethylimidazolidinone, dimethylacetamide, etc. They may also be usedas a mixed solvent.

Among these organic amide solvents, N-methylpyrrolidone or its mixedsolvent is particularly preferred from the viewpoint of the readiness inobtaining a melt-stable block copolymer, thermal and chemical stability,economy, etc.

B. Polymerization Process and Reaction Conditions

To prepare the PATE prepolymer in this invention, any processconventionally known for the polymerization of PATE can be adopted.However, for the reaction in which the PTK is formed in the presence ofthe PATE prepolymer, for the preparation of the PTK prepolymer and forthe reaction in which the PTK prepolymer and PATE prepolymer arecombined together to form a block copolymer, it is necessary to conductthe reactions under special conditions, namely, by maintaining a highwater content in the reaction systems, controlling the monomercompositions suitably, regulating the polymerization temperaturesappropriately, and limiting reaction time at high temperatures. It iseffective for the production of block copolymers having more preferablephysical properties, for example, to choose a suitable material for thereactor and to apply stabilization treatment in a final stage of thereaction.

Unless these reaction conditions are suitably controlled, it isdifficult to provide crystalline block copolymers having melt stabilitysuitable for conventional melt processing.

Preparation Processes of Prepolymers

(1) PATE Prepolymer

The PATE prepolymer employed as a raw material for the block copolymerof this invention can be prepared by having an alkali metal sulfide anda dihalogenated aromatic compound, which consists principally of adihalobenzene, undergo a dehalogenation/sulfuration reaction in thepresence of water in an organic amide solvent under the followingconditions (a)-(c):

(a) The ratio of the water content to the amount of the charged organicamide solvent is within a range of 0.2-5 (mol/kg), preferably 0.5-4.5(mol/kg).

(b) The ratio of the amount of the charged dihalogenated aromaticcompound to the amount of the charged alkali metal sulfide is within arange of 0.8-1.05 (mol/mol), preferably 0.8-1.0 (mol/mol), morepreferably 0.85-0.95 (mol/mol).

(c) The reaction is conducted at a temperature within a range of200°-280° C., preferably 210°-250° C., and should be continued until theaverage polymerization degree of the resulting prepolymer reaches atleast 10, preferably 20 or greater.

When the ratio of the amount of the charged dihalogenated aromaticcompound to the amount of the charged alkali metal sulfide is set at0.95 or greater (mol/mol), notably, 1.0 or greater (mol/mol) as theabove condition (b), the reaction product may be treated further withthe alkali metal sulfide to prepare a PATE prepolymer containing morethiolate groups as reactive terminal groups. The PATE prepolymer maycontain some crosslinked structure and/or branched structure introducedtypically by allowing a trihalobenzene or higher polyhalobenzene topresent in a small amount in the polymerization reaction system.

The PATE prepolymer is supposed to be a polymer having an averagepolymerization degree of at least 10, preferably at least 20 in view ofthe physical properties required for the block copolymer to be obtained.

In this invention, the number average molecular weight of the PATE blockin the stage of the prepolymer is determined by applying the methodwhich relies upon the numbers of terminal thiol groups, thiolate groupsand terminal halogen atoms.

Incidentally, it is preferred from the standpoint of reactivity that theratio of terminal thiolates, including thiol groups if any, to terminalhalogen atoms in the PATE prepolymer chain is at least 0.3 (mol/mol),more preferably at least 0.5 (mol/mol). If this ratio is smaller than0.3, the reactivity at the terminals of the PATE prepolymer isinsufficient thereby to make it difficult to obtain a block copolymer.

In passing, among the recurring units of the formula ##STR17## theparaphenylene sulfide unit of the formula ##STR18## is preferred becauseit can afford block copolymers excellent especially from the viewpointof crystallinity, melt stability, heat resistance, mechanical propertiesand the like.

(2) PTK Prepolymer

The PTK prepolymer employed as a raw material for the block copolymer ofthis invention can be prepared in the following manner.

Namely, the PTK prepolymer can be prepared by having an alkali metalsulfide and a dihalogenated aromatic compound, which consistsprincipally of 4,4'-dichlorobenzophenone and/or4,4'-dibromobenzophenone, undergo a dehalogenation/sulfuration reactionin the presence of water in an organic amide solvent under the followingconditions (a)-(b):

(a) The ratio of the water content to the amount of the charged organicamide solvent is within a range of 2.5-15 (mol/kg).

(b) The reaction is conducted at a temperature within a range of60°-300° C. with the proviso that the reaction time at 210° C. andhigher is not longer than 10 hours.

The PTK prepolymer may contain some crosslinked structure and/orbranched structure introduced typically by allowing atrihalobenzophenone or higher polyhalobenzophenone to present in a smallamount in the polymerization reaction system.

Production Process of Block Copolymers (Process No. 1)

As a production process for each block copolymer according to thisinvention, may be described the process in which a PATE prepolymer isprepared in advance and at least one PTK block is formed in the presenceof the PATE prepolymer. Practically, this process is the followingtwo-step process:

A process for the production of a poly(arylene thioether) blockcopolymer comprising (A) at least one poly(arylene thioether-ketone)block and (B) at least one poly(arylene thioether) block, whichcomprises at least the following two steps:

i) heating in the presence of water an organic amide solvent containinga dihalogenated aromatic compound, which consists principally of adihalobenzene, and an alkali metal sulfide, whereby a reaction mixturecontaining a poly(arylene thioether) prepolymer having predominantrecurring units of the formula ##STR19## and reactive terminal groups isformed, and ii) mixing the reaction mixture, which has been obtained inthe step i), with a dihalogenated aromatic compound consistingprincipally of at least one dihalogenzophenone selected from4,4'-dichlorobenzophenone and 4,4'-dibromobenzophenone, an alkali metalsulfide, an organic amide solvent and water and heating the resultantmixture to form a poly(arylene thioether-ketone) block havingpredominant recurring units of the formula ##STR20## wherein the --CO--and --S-- are in the para position to each other; said first and secondsteps i) and ii) being conducted under the following conditions (a)-(f):

(a) in the first step i), the ratio of the water content to the amountof the charged organic amide solvent being 0.2-5 (mol/kg), the ratio ofthe amount of the charged dihalogenated aromatic compound to the amountof the charged alkali metal sulfide being 0.8-1.05 (mol/mol), and thepolymerization being conducted until the average polymerization degreeof the poly(arylene thioether) prepolymer becomes at least 10, contentto the amount of the charged organic amide solvent being controlledwithin a range of 2.5-15 (mol/kg),

(c) in the second step, the ratio of the total amount of the chargeddihalogenated aromatic compound, said total amount being the amount ofthe whole dihalogenated aromatic compounds including the dihalobenzeneand the dihalobenzophenone to the total amount of the charged alkalimetal sulfide, said latter total amount being the total amount of thealkali metal sulfide charged in the first step i) and that charged inthe second step ii), being controlled within a range of 0.95-1.2(mol/mol),

(d) the ratio of the charged amount of the dihalogenated aromaticcompound consisting principally of the dihalobenzophenone to the chargedamount of the dihalogenated aromatic compound consisting principally ofthe dihalobenzene being controlled within a range of 0.1-10 (mol/mol),

(e) the reaction of the second step ii) being conducted within atemperature range of 150°-300° C. with the proviso that the reactiontime at 210° C. and higher is not longer than 10 hours, and

(f) in the second step ii), the reaction is conducted until the meltviscosity of the resulting block copolymer becomes 2-100,000 poises asmeasured at 350° C. and a shear rate of 1,200/sec.

Production Process of Block Copolymers (Process No. 2)

As another production process for each block copolymer according to thisinvention, may be described the process in which PATE prepolymer and PTKprepolymers are prepared in advance and are then reacted to combine themtogether. This process is practically the following 3-step process:

A process for the production of a poly(arylene thioether) blockcopolymer comprising (A) at least one poly(arylene thioether-ketone)block and (B) at least one poly(arylene thioether) block, whichcomprises at least the following three steps:

i) heating in the presence of water an organic amide solvent containinga dihalogenated aromatic compound, which consists principally of adihalobenzene, and an alkali metal sulfide, whereby a first reactionmixture containing a poly(arylene thioether) prepolymer havingpredominant recurring units of the formula ##STR21## and reactiveterminal groups is formed, ii) heating in the presence of water anorganic amide solvent containing a dihalogenated aromatic compound,which consists principally of at least one dihalobenzophenone selectedfrom 4,4'-dichlorobenzophenone and 4,4'-dibromobenzophenone, an alkalimetal sulfide, whereby a second reaction mixture containing apoly(arylene thioether-ketone) prepolymer having predominant recurringunits of the formula ##STR22## wherein the --CO-- and --S-- are in thepara position to each other and reactive terminal groups is formed, and

iii) mixing and reacting the first reaction mixture, which has beenobtained in the first step i) and contains the poly(arylene thioether)prepolymer, with the second reaction mixture obtained in the second stepii) and containing the poly(arylene thioetherketone) prepolymer;

said first through third steps i)-iii) being conducted under thefollowing conditions (a)-(g):

(a) in the first step i), the ratio of the water content to the amountof the charged organic amide solvent being 0.2-5 (mol/kg), the ratio ofthe amount of the charged dihalogenated aromatic compound to the amountof the charged alkali metal sulfide being 0.8-1.05 (mol/mol), and thepolymerization being conducted until the average polymerization degreeof the poly(arylene thioether) prepolymer becomes at least 10,

(b) in the second step, the ratio of the water content to the amount ofthe charged organic amide solvent being controlled within a range of2.5-15 (mol/kg) and the reaction being conducted within a temperaturerange of 60°-300° C. with the proviso that the reaction time at 210° C.and higher is not longer than 10 hours,

(c) in the third step, the ratio of the water content to the amount ofthe charged organic amide solvent being controlled within a range of2.5-15 (mol/kg)

(d) in the third step, the ratio of the total amount of the chargeddihalogenated aromatic compound, said total amount being the amount ofthe whole dihalogenated aromatic compounds including the dihalobenzeneand the dihalobenzophenone to the total amount of the charged alkalimetal sulfide, said latter total amount being the total amount of thealkali metal sulfide charged in the first step i) and that charged inthe second step ii), being controlled within a range of 0.95-1.2(mol/mol),

(e) the ratio of the whole poly(arylene thioether) prepolymer to thewhole poly(arylene thioether-ketone) prepolymer being controlled at0.05-5 by weight,

(f) the reaction of the third step iii) being conducted within atemperature range of 150°-300° C. with the proviso that the reactiontime at 210° C. and higher is not longer than 10 hours, and

(g) in the third step iii), the reaction is conducted until the meltviscosity of the resulting block copolymer becomes 2-100,000 poises asmeasured at 350° C. and a shear rate of 1,200/sec.

Reaction Conditions

The reaction conditions employed in the synthesis stages of the PTKprepolymer and block copolymer, said reaction conditions being essentialfeatures of the process of this invention for the production of theblock copolymer, will hereinafter be described in further detail.

(1) Water Content

In each of the processes for the preparation of the PTK prepolymer andblock copolymer of this invention, the water content in the reactionsystem may desirably be within a range of 2.5-15 moles, preferably3.5-14 moles per kg of the amount of the charged organic amide solvent.

Water contents lower than 2.5 moles can hardly provide a PTK prepolymeror block copolymer having high melt stability and moreover tend toinduce decomposition in the polymerization reactions. On the other hand,water contents higher than 15 moles result in a reduction in thereaction rates so that PTK prepolymer and block copolymer having a lowpolymerization degrees are only available.

In order to adjust the water content in a reaction system, the watercontent may be reduced by distillation or the like or may be increasedby adding water prior to the initiation of a polymerization reaction.

(2) Composition of Monomers Charged

The ratio of the total amount of the charged dihalogenated aromaticcompound to the total amount of the charged alkali metal sulfide is ofprimary importance with respect to the composition of charges in theprocess of this invention for the production of the block copolymer.

Here, the term "the total amount of the charged alkali metal sulfide"means the sum of the amount of the alkali metal sulfide charged uponsynthesis of the PTK prepolymer and/or the PATE prepolymer and theamount of the alkali metal sulfide charged upon synthesis of the blockcopolymer.

The ratio of the total amount of the dihalogenated aromatic compound tothe total amount of the alkali metal sulfide, both charged uponsynthesis of the block copolymer, may desirably be in a range of0.95-1.2 (mol/mol), more preferably 0.97-1.10 (mol/mol), most preferably0.98-1.05 (mol/mol).

Ratios smaller than 0.95 can hardly provide a block copolymer havingexcellent melt stability and tend to induce decomposition during thereaction. On the other hand, ratios greater than 1.2 can only provide ablock copolymer having a low molecular weight. Accordingly, such smallor large ratios are not preferred.

When a block copolymer is synthesized using only a portion or portionsof synthesized PTK prepolymer and/or PATE prepolymer, the amounts of thealkali metal sulfide and dihalogenated aromatic compound charged uponsynthesis of each prepolymer must be taken into consideration.

Regarding the ratio of the amount of the charged organic amide solventto the amount of the charged alkali metal sulfide in the composition ofcharges, it is desirable to charge the organic amide solvent in anamount of 0.3-5 kg, more preferably 0.5-3 kg per mole of the amount ofthe charged alkali metal sulfide. If the amount of the charged organicamide solvent is less than 0.3 kg/mol, the viscosity of the reactionsystem increases to render the stirring difficult, whereby decompositionreactions tend to occur due to localized heating. On the other hand, anyamounts of the charged organic amide solvent greater than 5 kg/molresult in poor productivity of the polymer per volume of the reactor andare hence economically disadvantageous. It is therefore necessary tocontrol the ratio of the total amount of the charged organic amidesolvent to the total amount of the charged alkali metal sulfide uponsynthesis of the block copolymer, too.

Where the alkali metal sulfide is lost by a distilling operation or thelike prior to the initiation of the reaction, the term "the amount ofthe charged alkali metal sulfide" as used herein means the remainingamount which is obtained by subtracting the loss from the amountactually charged. Furthermore, the term "the amount of the chargeddihalogenated aromatic compound" as used herein should be interpretednot to include the amount of the halogen-substituted aromatic compoundadded in the final stage of the reaction for effecting a stabilizingtreatment to be described subsequently.

(3) Reaction Temperature and Reaction Time

In the process of this invention for the preparation of the PTKprepolymer, the reaction is conducted at a temperature within a range of60°-300° C., with 150°-290° C. being preferred and 220°-280° C. morepreferred.

If the reaction temperature is lower than 60° C., it takes an undulylong period of time to obtain the PTK prepolymer. This is certainlydisadvantageous from the economical viewpoint. On the other hand, anyreaction temperatures higher than 300° C. are difficult to obtain a PTKprepolymer having excellent melt stability and moreover, involve apotential danger of decomposition during the reaction.

In the process of this invention for the production of the blockcopolymer, the reaction is conducted at a temperature in a range of150°-300° C., preferably 200°-290° C., and more preferably 210°-280° C.

Reaction temperatures lower than 150° C. require an unduly long time toobtain the block copolymer and are therefore economicallydisadvantageous. On the other hand, reaction temperatures higher than300° C. can hardly obtain the block copolymer in a form excellent inmelt stability and moreover involve a potential problem of decompositionduring the reaction.

The polymerization time required for obtaining a PTK prepolymer or blockcopolymer of a desired molecular weight becomes shorter as thepolymerization temperature increases but becomes longer as thepolymerization temperature decreases. Accordingly, It is generallyadvantageous to conduct the polymerization at a temperature of 210° C.or higher from the viewpoint of productivity. It is however notpreferred to conduct the reaction at a temperature of 210° C. or higherfor 10 hours or longer, because a PTK prepolymer or block copolymerhaving excellent melt stability can hardly be obtained under suchconditions.

In the present invention, the polymerization reaction is thereforecarried out at a temperature within the range of 150°-300° C. and thereaction time at 210° C. and higher is controlled within 10 hours.

(4) Reactor

In the process of this invention for the production of each of the PTKprepolymer and block copolymer, it is preferable to use, as a reactor(including equipment employed for provisional procedures of thepolymerization reaction, for example, those required for dehydration andthe like), a reactor which is made of a corrosion-resistant material atleast at portions with which the reaction mixture is brought into directcontact. The corrosion-resistant material is supposed to be inert sothat it does not react with the reaction mixture.

Preferable examples of the corrosion-resistant material include titaniummaterials such as titanium and titanium-containing alloys,nickel-containing corrosion-resistant materials such as Hastelloy C (aheat-resistant nickel alloy made by Haynes Stellite Company;nickel-molybdenum-chromium-iron-alloy containing about 55-60% of nickel,about 15-19% of molybdenum, about 13-16% of chromium) and austeniticsteels (for example, "Carpenter 20", a special austenitic steelcontaining about 28-38% of nickel, about 19-21% of chromium and about3-4% of copper and further, molybdenum, etc. in addition to iron.). Ofthese, it is particularly preferred to use a reactor lined with atitanium material.

The use of a reactor made of a corrosion-resistant material such as thatdescribed above makes it possible to obtain PTK prepolymer and blockcopolymer having high heat resistance and molecular weight.

(5) Treatment in the Final Stage of the Reaction

Although a melt-stable block copolymer can be obtained by theabove-described production process, the block copolymer can be obtainedin a form improved further in melt stability by adding a certain kind ofhalogen-substituted aromatic compound to the reaction system and causingit to undergo a reaction in a final stage of the reaction.

Here, it should be noted that the term "final stage of the reaction" asused herein means a period after the lapse of about one third of theoverall period of a reaction from the initiation thereof. Further, theamount of the halogen-substituted aromatic compound charged in the finalstage of the reaction is not included in the above-described amount ofthe charged dihalogenated aromatic compound.

As the halogen-substituted aromatic compound useful for the stabilizingtreatment in the final stage of the reaction, it is preferable to use atleast one halogen-substituted aromatic compound which contains at leastone group having electron-withdrawing property at least equal to --CO--group.

Illustrative examples of such a halogen-substituted aromatic compoundmay include bis(chlorobenzoyl)benzenes, bis(polychlorobenzoyl)benzenes,bis(bromobenzoyl)benzenes, bis(polybromobenzoyl)benzenes,4,4'-dichlorobenzophenone, 4,4'-dibromobenzophenone,dichlorobenzophenones other than the 4,4'-isomer, dibromobenzophenonesother than the 4,4'-isomer, difluorobenzophenones,dichlorodiphenylsulfones, dibromodiphenylsulfones,monochlorobenzophenones, monobromobenzophenones,monofluorobenzophenones, chloroacetophenones, dichloroacetophenones,chloronitrobenzenes and the like, and mixtures thereof.

Of these, 4,4'-dichlorobenzophenone and/or 4,4'-dibromobenzophenoneemployed as a monomer has excellent effects for the improvement of themelt stability, permits easy collection and purification of thethus-used organic amide solvent after the reaction and moreover, iseconomical. They are hence particularly preferred.

The halogen-substituted aromatic compound, which is used to effect thetreatment in the final stage of the reaction, may desirably be added inan amount of 0.1-100 moles, preferably 0.5-20 moles, more preferably1-10 moles per 100 moles of the charged alkali metal sulfide. If it isadded in any amounts smaller than 0.1 mole, it shows little effects forthe improvement of the melt stability. Even if it is added in anyamounts greater than 100 moles on the contrary, its improving effectstend to reach saturation. It is hence not economical to use it in such alarge amount.

It is desirable to conduct the final-stage treatment by adding theabove-mentioned halogen-substituted aromatic compound to thepolymerization reaction system in the final stage of the reaction andthen allowing it to react at 60°-300° C., more preferably 150°-290° C.,most preferably 220°-280° C. for 0.1-20 hours, more preferably 0.1-8hours. There is a potential problem that the reaction may not proceedsufficiently when the reaction temperature is lower than 60° C. or whenthe reaction time is shorter than 0.1 hour. On the other hand, there isanother potential problem that the melt stability of the block copolymeris reduced conversely when the reaction temperature is higher than 300°C. or when the reaction time is longer than 20 hours. Such reactiontemperatures and times are hence not preferred.

(6) Conditions for the Granulation

Another principal feature of the process of this invention for theproduction of the block copolymer resides in that the block copolymercan be obtained as granules by suitably choosing the aforementionedreaction conditions for the block copolymer further. Reaction conditionsfor obtaining at least 50 wt. % of the resulting block copolymer asgranules collectable by means of a sieve having an opening size of 75 μm(200 mesh) will next be described in further detail.

(i) Weight Ratio of the Total Amount of Block or Blocks (B) to the TotalAmount of Block or Blocks (A) in the Block Copolymer

The weight proportion of block or blocks (B) in the block copolymer isan important parameter since each block (B) contributes to thegranulation. When it is desire to obtain the block copolymer of thisinvention as granules, it is necessary to control the ratio of the totalamount of block or blocks (B) to the total amount of block or blocks (A)at 0.2 or greater, preferably 0.3 or greater, more preferably 0.4 orgreater, all by weight.

If this ratio is smaller than 0.2, it becomes difficult to obtain theblock copolymer as granules. On the contrary, ratios greater than 5however lead to a substantial reduction in the heat resistance of theblock copolymer. Such small and high ratios are both not preferred.

(ii) Reaction Temperature and Time for the Granulation

To obtain the block copolymer as granules, it is desirable to raise thereaction temperature to at least 240°-290° C., preferably 250°-280° C.in the course of the reaction or in a final stage of the reaction.

Reaction temperatures lower than 240° C. make it difficult to obtain theblock copolymer as granules. On the other hand, it is difficult toobtain the block copolymer in a form excellent in melt stability if thereaction temperature is higher than 290° C.

The time required for obtaining the block copolymer as desired granulesbecomes shorter as the reaction temperature increases. Conversely, itbecomes longer as the reaction temperature decreases. Therefore, it isgenerally advantageous from the viewpoint of productivity to conduct thereaction at a high temperature of 250° C. or higher. It however becomesdifficult to obtain the PTK prepolymer or block copolymer in a formexcellent in melt stability if the reaction at high temperatures of 250°C. and higher is continued for 7 hours or longer.

C. Collection of Block Copolymers

To collect the block copolymer from the reaction mixture, the followingmethod can be followed. Namely, after completion of the reactionincluding the treatment in the final stage if applied, the reactionmixture is subjected to flushing and/or distillation whereby the solventis removed either partly or wholly to concentrate the reaction mixture.If necessary, the concentrate may be heated to remove any remainingsolvent. The resulting solids or concentrate is washed with water and/oran organic solvent to eliminate soluble components such as salts formedin the reaction. The residue is again dried under heat to collect thepolymer.

By suitably choosing the reaction conditions in the process of thisinvention for the production of the block copolymer, at least 50 wt. %of the resulting block copolymer can be obtained as granules which canbe captured on a screen having an opening size of 75 μm (200 mesh), morepreferably 106 μm (140 mesh), most preferably 150 μm (100 mesh).

As has been described above, the block copolymer can be easily collectedas granules by a screen or the like from the reaction mixture aftercompletion of the reaction. The granular polymer thus collected iswashed with water and/or an organic solvent and then dried under heat toobtain it in a dry form. Since the block copolymer is in a granular formand has excellent handling property, it permits easy separation, waterwashing, transportation, metering and the like.

Stabilized Block Copolymers

Addition of a particular basic compound to the poly(arylene thioether)block copolymers of this invention makes it possible to reduce orprevent the melt viscosity increase, and crystallinity reduction, thedeposition of thermal decomposition products at resin-stagnatingportions of a melt-processing apparatus due to thermal modificationand/or thermal deterioration upon melt processing. Further, when thebasic compound is used in combination with a specific antioxidant, thesestabilizing effects are enhanced further.

The basic compound is non-oxidative and has heat resistance and lowvolatility. Specific examples include hydroxides, oxides and aromaticcarboxylates of group IIA metals of the periodic table other thanmagnesium, and aromatic carboxylates, carbonates, hydroxides,phosphates, including condensation products thereof, and borates,including condensation products thereof, of group IA metals of theperiodic table.

Among these basic compounds, the hydroxides and oxides of calcium andbarium, and the lithium, sodium and potassium salts of aromaticcarboxylic acids such as naphthalene mono- or poly-carboxylic acids,arylbenzoic acids, benzene mono- or poly-carboxylic acids, andhydroxybenzoic acid are preferred. Of these, calcium hydroxide andbarium hydroxide are particularly preferred.

The basic compound may be added in an amount of 0.1-30 parts by weight,preferably 0.2-25 parts by weight, more preferably 0.3-20 parts byweight per 100 parts by weight of the poly(arylene thioether) blockcopolymer. If the proportion of the basic compound is smaller than 0.1part by weight, its stabilizing effect cannot be brought aboutsufficiently. On the other hand, any proportions greater than 30 partsby weight have a potential problem such that the block copolymer may bedecomposed or its electrical characteristics may be deteriorated.

As the antioxidant usable in combination with the basic compound, thereis a radical chain terminating agent, peroxide decomposer or the like.Specific examples include hindered phenolic compounds, phosphoruscompounds and hindered amine compounds.

As typical hindered phenolic compounds, may be mentioned1,3,5-trimethyl-2,4,6-tris-(3,5-di-t-butyl-4-hydroxybenzyl)benzene andits analogous compounds, octadecyl3-(3,5-di-t-butyl-4-hydroxyphenyl)-propionate, pentaerythrityltetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate],2,2-thiodiethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate].

As phosphorus compounds, those containing a trivalent phosphorus atomcan be used preferably.

Of trivalent phosphorus compounds, representative examples includetris(2,4-di-t-butylphenyl) phosphite,bis-(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphite,distearyl pentaerythritol diphosphite, tetrakis(2,4-di-t-butylphenyl)4,4'-biphenylenediphosphinate.

Representative examples of the hindered amine compound includepoly[[6-(1,1,3,3-tetramethylbutyl)-imino-1,3,5-triazin-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidyl)imino]hexamethylene[(2,2,6,6-tetramethyl-4-piperidyl)imino]] and its analogous compounds.

As antioxidants, those having low volatility and decomposability arepreferred. In particular, the phosphorus compound referred to above canbe used preferably. These antioxidants may be used either singly or incombination. When two or more antioxidants are used in combination, thecombination of a radical chain terminating agent and a peroxidedecomposer is preferred.

The antioxidant may be added in an amount of 0-10 parts by weight,preferably 0.05-5 parts by weight, more preferably 0.1-3 parts by weightper 100 parts by weight of the poly(arylene thioether) block copolymer.If the antioxidant is added in an amount smaller than 0.05 part byweight, its stabilizing effect cannot be brought about sufficiently. Onthe other hand, any amounts greater than 10 parts by weight involve apotential danger such that more gas components may be formed orelectrical and other characteristics may be deteriorated.

Formed and Molded Products

The poly(arylene thioether) block copolymers and stabilized poly(arylenethioether) block copolymers of this invention can be formed or moldedinto various products by conventional melt-processing techniques.

Extruded Molded Products

Various extruded products can be obtained, for example, by charging ablock copolymer of this invention into an extruder equipped with ashaping die or nozzle in air or preferably in an inert gas atmosphere,extruding and shaping the block copolymer at a cylinder temperature of300°-420° C. and an average intracylinder resin residence time of 0.5-60minutes, preferably 2-30 minutes, and if necessary annealing theextrudates at 150°-350° C. for 0.1-100 hours.

Injection-molded Products

Various injection-molded products can be obtained, for example, bycharging a block copolymer of this invention into an injection moldingmachine equipped with a mold in air or preferably in an inert gasatmosphere, injection-molding the block copolymer at a cylindertemperature of 300°-420° C., a mold temperature of 50°-230° C., anaverage intracylinder resin residence time of 1-3,000 seconds,preferably 3-1,000 seconds, an injection holding pressure of 10-10⁴kg/cm² and an injection cycle of 1-3,000 seconds, and if necessaryannealing the thus-injected products at 150°-350° C. for 0.1-100 hours.

Unstretched Films

An unstretched film can be obtained, for example, by charging a blockcopolymer of this invention into an extruder equipped with a T-die inair or preferably in an inert gas atmosphere and melt-extruding it intoa film-like shape (T-die process) or pressing the block copolymer into afilm-like shape on a high-temperature press while heating it in a moltenstate (hot pressing), and if necessary, heat-setting the resultant filmfor 1-3,000 seconds at a temperature of 160°-350° C. under a stress(pressure) while limiting distortions within ±20%, and if necessaryfurther heat-relaxing the heat-set film at 150°-340° C. for 1-3,000seconds under substantially no stress. It is also possible to obtain anunstretched film by subjecting the poly(arylene thioether) blockcopolymer to blown-film extrusion or compression molding. A blockcopolymer of the present invention can also be combined with one or moreother resins to form a multilayer film.

Unstretched films according to this invention generally have an averagethickness of 0.5-5,000 μm, preferably 1-3,000 μm.

Incidentally, it is preferred that such extruder, injection-moldingmachine and T-die equipped extruder be made of a corrosion-resistantmetal at portions where they may be brought into contact with the resinmelt. Preferably, they should be vented.

Other Melt-formed or Melt-molded Products

From the block copolymers according to this invention, formed or moldedhollow products such as bottles, tanks, pipes and tubes can be obtainedby blow molding or the like. By pultrusion or the like, elongatedproducts such as plates, pipes, rods and profiles can also be obtainedfrom them.

Application Fields

The block copolymers of the present invention are crystalline and permitthe application of conventional melt processing techniques. They can beformed or molded into various heat-resistant products and can then beused in various fields.

For example, extrusion products may include sheets, plates, pipes,tubes, covered conductors, etc. Injection-molded products may be used aselectronic and electric parts, car parts, etc. On the other hand,unstretched films may be employed as base films for magnetic recording,capacitor films, printed circuit boards, insulating films, prepregsheets, and so on.

ADVANTAGES OF THE INVENTION

The present invention can economically provide poly(arylene thioether)block copolymers which have excellent heat resistance, processabilityand handling property and are crystalline. The invention can alsoprovide stabilized poly(arylene thioether) block copolymers. Theinvention can also provide various formed or molded products of suchpoly(arylenethioether) block copolymers.

EMBODIMENTS OF THE INVENTION

The present invention will hereinafter be described in further detail bythe following examples and comparative examples. It should however beborne in mind that the present invention is not limited only to thefollowing examples.

EXAMPLE 1 Production Process No. 1 Synthesis of PATE Prepolymer

A titanium-lined reactor was charged with 3.2 kg of hydrated sodiumsulfide (water content: 54.0 wt. %) and 6.5 kg of N-methylpyrrolidone(hereinafter abbreviated as "NMP"). While gradually heating the contentsto 203° C. in a nitrogen gas atmosphere, 2.45 kg of an NMP solution,which contained 1.358 kg of water, and 13.4 g of hydrogen sulfide Weredistilled out. Thereafter, 0.142 kg of water was added. A liquid mixtureconsisting of 2.443 kg of p-dichlorobenzene (hereinafter abbreviated as"PDCB") and 3.82 kg of NMP was then fed, followed by polymerization at220° C. for 10 hours (PDCB/sodium sulfide=0.9 mol/mol; watercontent/NMP=3.1 mol/kg), whereby about 13.6 kg of a reaction slurry (S₁)containing a prepolymer (P₁) for poly(p-phenylene thioether)(hereinafter abbreviated as "PPTE") were obtained.

A portion of the reaction slurry was sampled out, and the amount ofremaining PDCB, terminal thiolate groups, terminal thiol groups andterminal chlorine groups were measured respectively by methods whichwill be set out subsequently.

The amount of PDCB remaining in the reaction slurry as determined by gaschromatography was 0.3 wt. % of the charged amount. The concentration ofterminal thiolate groups and terminal thiol groups was 439×10⁻⁶equivalent per gram of Prepolymer P₁, while the concentration ofterminal chlorine groups was 29×10⁻⁶ equivalent per gram of PrepolymerP₁. The number average molecular weight of Prepolymer P₁ as determinedfrom the numbers of those terminal groups was 4274 (averagepolymerization degree: 40).

Analytical Methods Analysis of Terminal Thiol Groups or Thiolate Groups

Immediately after completion of the polymerization of the prepolymer, aportion of the reaction slurry was sampled out and then poured intowater to have the prepolymer precipitated. The prepolymer was collectedby filtration, washed in distilled water and then treated with dilutehydrochloric acid, whereby terminal thiolate groups were converted intothiol groups. The resulting prepolymer was washed for 30 minutes indistilled water and for additional 30 minutes in acetone and then driedat room temperature under reduced pressure in a vacuum drier, therebyobtaining a prepolymer sample. Right after that, about 10 mg to 1 gramof the prepolymer was weighed and placed in a stopper-equipped testtube, followed by the addition of 2.5 ml of an acetone solutionconsisting of 2.5 ml of acetone and 50 mmol of iodoacetamide. The testtube was hermetically closed and then heated at 100° C. for 60 minutes.The test tube was thereafter cooled with water and opened. Theliquid-phase portion was separated. The absorbance at 450 nm (i.e., theabsorbance of iodine) was measured by means of a spectrophotometer.Using a calibration curve prepared in advance with respect to the thiolcompound ##STR23## as a standard, the concentration of terminal thiolgroups was calculated from the absorbance. (The amount of each sampleshould be chosen suitably so that the concentration of thiol groups in acorresponding acetone slurry falls within a range of 0.1-0.3 mmol.)Analysis was conducted three times on the same dried sample to determinethe average value of the concentration of terminal thiol groups.

Analysis of Terminal Halogen Groups

Quantitative analysis of terminal halogen atoms was conducted using anX-ray fluorescence analyzer (model: "3080E2"; manufactured by RigakuDenki Kabushiki Kaisha).

Determination of Number Average Molecular Weight

Each number average molecular weight was determined from the data ofterminal thiol groups, including thiolate groups, and halogen groups inaccordance with the following equation: ##EQU1##

In addition, from each number average molecular weight, itscorresponding average polymerization degree was calculated.

Synthesis of Block Copolymer

A titanium-lined 20-l reactor was charged with 247.7 g of hydratedsodium sulfide (water content: 54.0 wt. %), 688 g of4,4'-dichlorobenzophenone (hereinafter abbreviated as "DCBP"), 8.212 kgof the reaction slurry (S₁) described above, 2.93 kg of NMP and 1.09 kgof water. After the reactor being purged with nitrogen gas, the contentswere heated to 260° C. at which they were polymerized for 2 hours.

The reaction conditions upon synthesis of the block copolymer were asfollows:

(1) The molar ratio of the total amount of the charged dihalogenatedaromatic compounds [the sum of the amount of PDCB charged upon synthesisof the prepolymer (P₁) and the amount of DCBP charged upon synthesis ofthe block copolymer] to the total amount of the charged alkali metalsulfide [the sum of the amount of effective sodium sulfide charged uponsynthesis of the prepolymer (P₁) and the amount of sodium sulfidecharged upon synthesis of the block copolymer] was 1.01.

(2) The ratio of the amount of DCBP to the amount of PDCB charged uponsynthesis of the prepolymer (P₁), was about 0.47 (=32/68) by weight andabout 0.28 by mole.

(3) The ratio of the water content to the organic amide (NMP) was about10 mol/kg.

Collection of Block Copolymer

The resultant reaction mixture in the form of a slurry was diluted witha substantially equiamount of NMP and the granular polymer thus obtainedwas collected by a screen having an opening size of 150 μm (100 mesh).The polymer was washed three times with NMP and further three times withwater, and then dried at 100° C. for 24 hours under reduced pressure toobtain a block copolymer (B₁). The collection rate of the blockcopolymer (B₁) was 80%.

Inherent Properties of Block Copolymer B₁

The block copolymer (B₁) was in the form of pearl-like granules havingan average size of 711 μm and had a bulk density of 0.58 g/dl.

By an infrared (IR) spectrum analysis, a strong absorption peakattributed to ketone group was observed at 1640 cm⁻¹. Wide angle X-raydiffraction which was conducted using "RAD-B System" manufactured byRigaku Denki Kabushiki Kaisha showed a diffraction pattern correspondingto the block copolymer, said pattern being apparently different fromthat corresponding PATE homopolymer or PTK homopolymer or a blendthereof.

The content of sulfur in Block Copolymer B₁ was determined by thecombustion flask method and ion chromatography (IC method). Namely,Block Copolymer B₁ was caused to burn in a flask and the resultingcombustion gas was absorbed in aqueous hydrogen peroxide solution,whereby the sulfur content of the block copolymer was converted intosulfate groups. The sulfur content was then quantitatively analyzedusing an ion chromatographic apparatus equipped with an electricalconductivity detector ("IC-500"; manufactured by Yokogawa ElectricCorporation).

The weight fraction W_(b) (wt. %) of the recurring units ##STR24## inthe block copolymer can be calculated in accordance with the followingequation: ##EQU2##

By introducing a measured value W=25.3% and calculated values W₁ =15.01%and W₂ =29.63% into the above equation, W_(b) was determined to be 70%.

Physical Properties of Block Copolymer

The melt viscosity of Block Copolymer B₁ was 250 poises. Tmc and ΔHmcare shown in Table 1.

EXAMPLES 2-8 Production Process No. 1 Synthesis of PATE Prepolymer

A reaction slurry (S₂) containing Prepolymer P₂ of poly(p-phenylenethioether) (PPTE) was obtained in the same manner as in Example 1. Thenumber average molecular weight of Prepolymer P₂ was 3760 (averagepolymerization degree: 35).

Syntheses of Block Copolymers B₂ -B₈

Polymerization, post treatment and drying were conducted by adding waterand NMP to give the same polymerization conditions as in Example 1except that hydrated sodium sulfide (water content: 54.0 wt. %), DCBPand the reaction slurry (S₂) were charged into a 1-l autoclave to givethe respective ratios of (b) recurring units ##STR25## to (a) recurringunits ##STR26## given in Table 1.

Physical Properties of Block Copolymers

The measurement results are summarized in Table 1. Incidentally, themelt viscosities of Block Copolymers B₂, B₄ and B₈ were 410 poises, 390poises and 180 poises, respectively.

EXAMPLE 9 Production Process No. 1

Polymerization was conducted under the same conditions as in Example 6except that the polymerization temperature and time were changed from260° C. and 2 hours to 230° C. and 5 hours. The reactor was cooled. Thereaction mixture in the form of a slurry was taken out of the reactorand was passed through a screen having an opening size of 75 μm (200mesh). No granular polymer was collected at all. That slurry was pouredinto about 3 liters of acetone to have the polymer precipitated. Thethus-precipitated polymer was collected on a filter paper (class: 5A),washed twice with acetone and additionally twice with water. Acetone andwater were removed to obtain the polymer in a wet form. The wet polymerwas dried at 100° C. to obtain a block copolymer (B₉) as a fine powder.The melt viscosity of Block Copolymer B₉ was 35 poises.

The measurement results of physical properties and the like arecollectively given in Table 1.

COMPARATIVE EXAMPLE 1 Synthesis of PTK Homopolymer

A titanium-lined reactor was charged with 9.0 moles of DCBP, 9.0 molesof hydrated sodium sulfide (water content: 53.6 wt. %) and 9.0 kg ofNMP. After the reactor being purged with nitrogen gas, the resultantmixture was maintained at 240° C. for 2 hours and at 260° C. for 30minutes to react them (water content/NMP=5.0 mol/kg). The reactor wascooled, and the reaction mixture in the form of a slurry was taken outof the reactor. A portion of the slurry was passed through a screenhaving an opening size of 75 μm (200 mesh). However, no granular polymerwas collected at all.

The remaining slurry was poured into about 20 liters of acetone to havethe resultant polymer precipitated. The polymer was collected byfiltration, and then washed twice with acetone and additionally twicewith water. Acetone and water were removed to obtain the polymer in awet form. The wet polymer was dried at 80° C. for 24 hours under reducedpressure, thereby obtaining a polymer (R₁) as an ivory powder.

The particle size of Polymer R₁ thus obtained was measured by an imageanalyzer ("OMNICON", trade mark; manufactured by Shimadzu Corp.). Theaverage particle size was 10.6 μm. Particles not greater than 6 μmamounted to 60.5 wt. %. On the other hand, particles of 30 μm andgreater accounted for 0.4 wt. % only. The bulk density of Polymer R₁ was0.24 g/dl.

Polymer R₁ thus obtained was soluble in 98% concentrated sulfuric acidbut was insoluble in α-chloronaphthalene even at 225° C.

COMPARATIVE EXAMPLE 2 Experimental Granulation by Co- and Re-Dissolutionof Homopolymers

A titanium-lined 1-l reactor was charged with 35 g of fine particulatePTK Polymer R₁ obtained in Comparative Example 1 and 65 g ofpoly(p-phenylene thioether) ("FORTRON #W214", trade name: product ofKureha Chemical Industry Co., Ltd.) and further with 500 g of NMP and 45g of water. The contents were maintained at 260° C. for 2 hours. Aftercooling, the resultant slurry was passed through a screen having anopening size of 75 μm (200 mesh) to collect a particulate polymer. Fromthe filtrate, a fine particulate polymer was also collected using afilter paper (class: 5A).

The polymers thus collected were separately washed and dried in asimilar manner to Example 1, thereby obtaining 51 g of granular PolymerR₂ and 37 g of fine particulate polymer.

Like poly(p-phenylene thioether), granular Polymer R₂ was insoluble in98% concentrated sulfuric acid but soluble at 225° C. inα-chloronaphthalene. Its transition temperature was substantially thesame as that of poly(p-phenylene thioether).

COMPARATIVE EXAMPLE 3 Synthesis of Random Copolymer

A titanium-lined 1-l reactor was charged with 0.4 mole of DCBP, 0.5 moleof hydrated sodium sulfide (water content: 54.0 wt. %), 0.1 mole of PDCBand 500 g of NMP. They were reacted at 260° C. for 2 hours [watercontent/NMP=5 mol/kg, DCBP/PDCB=87/13 (weight ratio)].

The reaction mixture in the form of a slurry, said mixture containing arandom copolymer (R₃), had a dark brown color and gave off an odor ofdecomposed polymers.

As a result of a gas chromatographic analysis, the remaining monomer wasfound to be PDCB. Its amount was equal to 33% of the amount charged. Theslurry as the reaction mixture was passed through a screen having anopening size of 75 μm (200 mesh). It was however unable to collect anygranular polymer.

COMPARATIVE EXAMPLE 4 Synthesis of Random Copolymer

Polymerization was conducted in a similar manner to Comparative Example3 except that 0.1 mole of DCBP and 0.4 mole of PDCB were charged in lieuof 0.4 mole of DCBP and 0.1 mole of PDCB [water content/NMP =5 mol/kg,DCBP/PDCB=30/70 (weight ratio)].

The reaction mixture in the form of a slurry had a dark red color andgave off an offensive odor. The slurry was passed through a screenhaving an opening size of 75 μm (200 mesh). It was however unable tocollect any granular polymer. A fine powdery polymer was recovered fromthe filtrate by using a filter paper (class: 5A) and was then washed anddried in a similar manner to Example 1. Tm of the resulting randomcopolymer (R₄) was 240° C., which was much lower than the melting pointsof poly(p-phenylene thioether) and PTK homopolymer.

COMPARATIVE EXAMPLE 5 Experimental Formation of Granules byRedissolution of PTK

A titanium-lined 1-l reactor was charged with 106 g of the fine powderyPTK polymer obtained in Comparative Example 1 and also with 500 g of NMPand 45 g of water. The contents were maintained at 260° C. for 2 hours.After the reactor being cooled, the resulting size of 75 μm (200 mesh).It was however unable to collect any granular polymer.

COMPARATIVE EXAMPLE 6 Synthesis of PTK Homopolymer

A titanium-lined 1-l reactor was charged with 0.5 mole of DCBP, 0.5 moleof hydrated sodium sulfide (water content: 54.0 wt. %) and 500 g of NMP.After the reactor being purged with nitrogen gas, the contents weremaintained at 260° C. for 2 hours to react them. The reactor was cooledand the reaction mixture in the form of a slurry was passed through ascreen having an opening size of 75 μm (200 mesh). It was however unableto collect any granular polymer.

EXAMPLE 10 Production Process No. 2 Synthesis of PTK Prepolymer

A titanium-lined 1-l reactor was charged with 0.531 mole of DCBP, 0.282mole of hydrated sodium sulfide (water content: 54.0 wt. %), 77 g ofwater and 511 g of NMP. After the reactor being purged with nitrogengas, the contents were maintained at 200° C. for 1 hours to react them(water content/NMP=about 11 mol/kg), whereby a reaction slurry (KS₁)containing a PTK prepolymer (K₁) was obtained.

Synthesis of Block Copolymer

A titanium-lined 1-l reactor was charged with 489.5 g of Reaction SlurryS₂ containing PPTE Prepolymer P₂, 315.4 g of Reaction Slurry KS₁containing PTK Prepolymer K₁ and 31.7 g of water. After the reactorbeing purged with nitrogen gas, the contents were maintained at 260° C.for 2 hours.

The reaction conditions upon synthesis of the block copolymer were asfollows:

(1) The molar ratio of the total amount of the charged dihalogenatedaromatic compounds [the sum of the amount of PDCB charged upon synthesisof Prepolymer P₂ and the amount of DCBP charged upon synthesis of PTKPrepolymer K₁ ] to the total amount of the charged alkali metal sulfide[the sum of the amount of sodium sulfide charged upon synthesis ofPrepolymer P₂ and the amount of sodium sulfide charged upon synthesis ofPTK Prepolymer K₁ ] was 1.04.

(2) The ratio of PATE blocks to PTK blocks was 58:42 (weight ratio).

(3) The ratio of the water content to the organic amide (NMP) was about9.5 mol/kg.

Collection of Block Copolymer

The resultant reaction mixture in the form of a slurry was diluted witha substantially equiamount of NMP and the granular polymer thus obtainedwas collected by a screen having an opening size of 150 μm (100 mesh).The polymer was washed three times with NMP and further three times withwater, and then dried at 100° C. for 24 hours under reduced pressure toobtain a pearl-like block copolymer (B₁₀) having an average size of 683μm. The collection rate of the block copolymer (B₁₀) was 78%.

Physical Properties of Block Copolymer

The melt viscosity of Block Copolymer (B₁₀) was 199 poises. Its Tmc,ΔHmc and the like are collectively shown in Table 1.

                                      TABLE 1                                     __________________________________________________________________________                                            Crystallinity · melt                                                 stability                                      PATE recurring units/PTK recurring units                                                           Transition                                                                              [400° C.]                                                                      [400° C./10 min]       Polymer  Charged value                                                                          Analyzed value                                                                            temp. (°C.)                                                                      Tmc ΔHmc                                                                        Tmc ΔHmc                    code (weight ratio)                                                                         (weight ratio)                                                                            Tg.sup.1)                                                                          Tm.sup.2)                                                                          (°C.)                                                                      (J/g)                                                                             (°C.)                                                                      (J/g)                     __________________________________________________________________________    Ex. 1                                                                             B.sub.1                                                                            1.9 (65/35)                                                                            2.3 (70/30) 95   331/293                                                                            260 50  226 42                        Ex. 2                                                                             B.sub.2                                                                            0.1 (13/87)                                                                            0.2 (14/86) 125  348  301 55  240 44                        Ex. 3                                                                             B.sub.3                                                                            0.3 (25/75)                                                                            0.4 (26/74) 117  344  285 53  240 42                        Ex. 4                                                                             B.sub.4                                                                            0.7 (40/60)                                                                            0.7 (42/58) 110  339  280 54  237 43                        Ex. 5                                                                             B.sub.5                                                                            1.0 (50/50)                                                                            1.1 (53/47) 106  326  271 50  233 42                        Ex. 6                                                                             B.sub.6                                                                            1.5 (60/40)                                                                            1.7 (63/37) 103  324/295                                                                            265 50  234 41                        Ex. 7                                                                             B.sub.7                                                                            2.3 (70/30)                                                                            2.6 (72/28) 95   320/293                                                                            258 48  225 40                        Ex. 8                                                                             B.sub.8                                                                            4.0 (80/20)                                                                            4.3 (81/19) 92   318/293                                                                            250 45  223 35                        Ex. 9                                                                             B.sub. 9                                                                           1.5 (60/40)                                                                            1.6 (61/39) 103  322/294                                                                            268 53  242 45                        Ex. 10                                                                            B.sub.10                                                                           1.4 (58/42)                                                                            1.6 (62/38) 101  326/296                                                                            260 51  218 34                        Comp.                                                                             R.sub.1                                                                            0 (0/100)                                                                              Homopolymer 135  360  320 60  313 55                        Ex. 1                                                                         Comp.                                                                             R.sub.2                                                                            1.9 (65/35)                                                                            Blend       86   293  --  --  --  --                        Ex. 2                         (PATE)                                                                             (PATE)                                     Comp.                                                                             R.sub.3                                                                            0.1 (11/89)                                                                            Random copolymer                                                                          --   --   --  --  --  --                        Ex. 3             (uncollectable)                                             Comp.                                                                             R.sub.4                                                                            2.0 (67/33)                                                                            Random copolymer                                                                          --   240  --  --  --  --                        Ex. 4                                                                         Comp.                                                                             R.sub.5                                                                            0 (0/100)                                                                              Homopolymer 140  363  --  --  --  --                        Ex. 5                                                                         Ref.                                                                              .sup.3)                                                                            (100/0)  PATE homopolymer                                                                          85   293  238 30  218 25                        Ex.                                                                           __________________________________________________________________________                             Collection rate of polymer                                               Polymer                                                                            (%) Screen opening                                                       code 150 μm                                                                           75 μm                                                                             Collectability                                                                       Remarks                          __________________________________________________________________________                    Ex. 1                                                                             B.sub.1                                                                            80    --     Excellent                                                                            Production Process                                                            No. 1                                            Ex. 2                                                                             B.sub.2                                                                            --    <10    Fair   Production Process                                                            No. 1                                            Ex. 3                                                                             B.sub.3                                                                            --    54     Good   Production Process                                                            No. 1                                            Ex. 4                                                                             B.sub.4                                                                            --    70     Good   Production Process                                                            No. 1                                            Ex. 5                                                                             B.sub.5                                                                            72    --     Excellent                                                                            Production Process                                                            No. 1                                            Ex. 6                                                                             B.sub.6                                                                            70    --     Excellent                                                                            Production Process                                                            No. 1                                            Ex. 7                                                                             B.sub.7                                                                            80    --     Excellent                                                                            Production Process                                                            No. 1                                            Ex. 8                                                                             B.sub.8                                                                            86    --     Excellent                                                                            Production Process                                                            No. 1                                            Ex. 9                                                                             B.sub.9                                                                            0     0      Poor   Fine powder                                      Ex. 10                                                                            B.sub.10                                                                           78    --     Excellent                                                                            Production Process                                                            No. 2                                            Comp.                                                                             R.sub.1                                                                            0     0      Poor   Fine powder                                      Ex. 1                                                                         Comp.                                                                             R.sub.2                                                                            58    --     Good   PATE alone collected                             Ex. 2                        as granules                                      Comp.                                                                             R.sub.3                                                                            0     0      Poor   Offensive odor.                                  Ex. 3                        Poor copolymerizability                          Comp.                                                                             R.sub.4                                                                            0     0      Poor   Offensive odor                                   Ex. 4                                                                         Comp.                                                                             R.sub.5                                                                            0     0      Poor   Fine powder                                      Ex. 5                                                                         Ref.                                                                              .sup.3)                                                                            --    --     --     Granular                                         Ex.                                                           __________________________________________________________________________     .sup.1) Glass transition temperature, Tg as determined by DSC at a heatin     rate of 10° C./min by using a quenchpressed sheet (pressed at          380° C.) as a sample.                                                  .sup.2) Melting point, Tm as determined by DSC at a heating rate of           10° C./min.                                                            .sup.3) "FORTRON #W214", poly(pphenylene thioether) produced by Kureha        Chemical Industry Co., Ltd.                                              

EXAMPLE 11 Production Process No. 2 Synthesis of PATE Prepolymer

A titanium-lined reactor was charged with 3.2 kg of hydrated sodiumsulfide (water content: 53.7 wt. %) and 6.0 kg of NMP. While graduallyheating the contents to 200° C. under a nitrogen gas atmosphere, 2.541kg of an NMP solution containing 1.326 kg of water and 0.38 mole ofhydrogen sulfide were distilled out. Then, 0.123 kg of water was added,followed by the feeding of a mixed solution of 2.35 kg of PDCB and 4.51kg of NMP. Polymerization was conducted at 220° C. for 10 hours(PDCB/sodium sulfide=0.86 mol/mol, water content/NMP=about 3 mol/kg),thereby obtaining a reaction slurry (S₃) containing a PPTE prepolymer(P₃). The number average molecular weight of Prepolymer P₃ was 1530(average polymerization degree: 14).

Synthesis of PTK Prepolymer

A titanium-lined 20-l reactor was charged with 3.640 moles of DCBP,2.039 moles of hydrated sodium sulfide (water content: 53.7 wt. %), 176g of water and 4.004 kg of NMP. After the reactor being purged withnitrogen gas, the contents were maintained at 220° C. for 1 hour (watercontent/NMP =about 5 mol/kg) to obtain a reaction slurry (KS₂)containing a PTK prepolymer (K₂).

Synthesis of Block Copolymer

A charge pot equipped with a heater was mounted on the titanium-lined20-l reactor with Reaction Slurry KS₂ containing PTK Prepolymer K₂(temperature of slurry: 220° C.). The pot was charged with 9.12 kg ofReaction Slurry S₃ containing PPTE Prepolymer P₃. After Reaction SlurryS₃ being heated to 220° C., the with 1146 g of water. The contents werethereafter mixed.

The contents were maintained at 260° C. for 2 hours. After the contentsbeing allowed to cool down to 240° C., a final treatment of the reactionwas conducted. The final stabilizing treatment of the reaction waseffected by adding 0.4356 mole of DCBP and 0.5 kg of NMP and thenreacting the contents at 240° C. for 0.2 hour.

The reaction conditions upon synthesis of the block copolymer were asfollows:

(1) The molar ratio of the total amount of the charged dihalogenatedaromatic compounds [the sum of the amount of PDCB charged upon synthesisof Prepolymer P₃ and the amount of DCBP charged upon synthesis of PTKPrepolymer K₂ ] to the total amount of the charged alkali metal sulfide[the sum of the amount of sodium sulfide charged upon synthesis ofPrepolymer P₃ and the amount of sodium sulfide charged upon synthesis ofPTK Prepolymer K₂ ] was 0.99.

(2) The ratio of PATE blocks to PTK blocks was approximately 60:40(weight ratio).

(3) The ratio of the water content to the organic amide (NMP) was about10 mol/kg.

Collection of Block Copolymer

Collection was conducted in a similar manner to Example 10, therebyobtaining a block copolymer (B₁₁). The collection rate was 78%.

Physical Properties of Block Copolymer

Physical properties of Block Copolymer B₁₁ were as follows:

Melt viscosity: 650 poises.

Transition temperature:

Tg: 104° C.

Tm: 301° C. and 324° C.

Melt crystallization temperature:

Tmc (400° C.): 252° C.

Tmc (400° C./10 min): 221° C.

Melt crystallization enthalpy:

ΔHmc (400° C.): 43 J/g.

Residual melt crystallization enthalpy:

ΔHmc (400° C./10 min): 36 J/g.

Incidentally, the ratio (weight ratio) of the sum of PATE recurringunits to the sum of PTK recurring units was 1.6 (62/38).

Solubility of Block Copolymers in Solvent

Block Copolymer B₁₁, Block Copolymer B₁ synthesized in Example 1, PTKHomopolymer R₁ synthesized in Comparative Example 1 and poly(p-phenylenethioether) ("FORTRON #W214"; product of Kureha Chemical Industry Co.,Ltd.) were separately hot-pressed and then cooled to form amorphoussheets. The respective amorphous sheets were placed in the solventsshown in Table 2 to investigate their dissolution behavior.

As given in Table 2, the block copolymers have properties different fromPTK homopolymer and poly(p-phenylene thioether) which are homopolymersof the components of the block copolymers.

                                      TABLE 2                                     __________________________________________________________________________                     Solvent                                                                       98 wt. % conc.      p-Chlorophenol/1,2,4-trichlorobenzene                                         1                                                         sulfuric acid                                                                         α-chloronaphthalene                                                                 mixed solvent (50/50 weight ratio)                        Room    Room        Room       190° C..sup.1)                                                         →                                                                             190°                                                                   C..sup.2)                                                                     →               Dissolution temperature                                                                        temperature                                                                           temperature                                                                          225° C.                                                                     temperature                                                                          190° C.                                                                    room temp.                                                                           150°            __________________________________________________________________________                                                           C.                     Polymer                                                                            Block copolymer, B.sub.11                                                                 X       X      X    X      ◯                                                                     Precipitated                                                                         ◯               Block copolymer, B.sub.1                                                                  X       X      X    X      ◯                                                                     Precipitated                                                                         ◯               PTK homopolymer, R.sub.1                                                                  ◯                                                                         X      X    X      ◯                                                                     ◯                                                                        ◯               Poly(p-phenylene                                                                          X       X      ◯                                                                      X      X   X      X                           thioether)                                                               __________________________________________________________________________     X: Insoluble.                                                                 ◯: Soluble (to complete clearness to the vision).                 .sup.1) State when maintained at room temperature for 2 hours after a         solubilizing operation was conducted at 190° C. for 5 minutes.         .sup.2) State when maintained at 150° C. for 2 hours after a           solubilizing operation was conducted at 190° C. for 5 minutes.    

EXAMPLE 12 Production Process No. 2

A block copolymer (B12) was obtained by conducting a reaction and afinal treatment in a similar manner to Example 11 except that the ratioof the charged amount of PDCB to the charged amount of sodium sulfideupon synthesis of a PATE prepolymer was changed to 0.94 (mol/mol) andthe ratio of the charged amount of DCBP to the charged amount of sodiumsulfide upon synthesis of a PTK prepolymer was also adjusted to controlthe molar ratio of the total amount of the charged dihalogenatedaromatic compound to the total amount of the charged alkali metalsulfide upon synthesis of the block copolymer to 1.01. The collectionrate was 77%.

Physical Properties of Block Copolymer

Physical properties of Block Copolymer B₁₂ were as follows:

Melt viscosity: 350 poises.

Melt crystallization temperature:

Tmc (400° C./10 min): 228° C.

Residual melt crystallization enthalpy:

ΔHmc (400° C./10 min): 40 J/g.

Incidentally, the ratio (weight ratio) of the sum of PATE recurringunits to the sum of PTK recurring units was 1.3 (63/47).

EXAMPLE 13 Melt Stabilization (1) of Block Copolymer by the Addition ofStabilizer

The melt stability of Block Copolymer B₁ synthesized in Example 1 wasinvestigated by adding various basic compounds thereto.

Namely, the various basic compounds were separately added as dry powdersto Block Copolymer B₁. Each mixture was blended in a tumbler blender andthen charged into a single-screw extruder having a cylinder diameter of19 mm and an L/D ratio of 25. It was molten and kneaded at a cylindertemperature of 350° C. and thereafter extruded in the form of strands.The strands were cooled and then chopped. Thus, pellet samples of themixtures of the block copolymer and the individual basic compounds wereprepared. They were used as samples for the evaluation of meltstability.

Evaluation of the melt stability of each stabilizer-added pellet samplewas conducted in the following manner. Namely, about 20 g of the pelletwere placed in a barrel of Capirograph, which was heated at 350° C. Meltviscosities η*₅, η*₃₀ and η*₆₀ upon elapsed time of 5 minutes, 30minutes and 60 minutes, respectively were measured at a shear rate of1200 sec⁻¹ to determine η*₃₀ /η*₅ and η*₆₀ /η*₅. As these ratios becomecloser to 1, better melt stability is indicated. In addition, therespective melt viscosities and their ratios were also determined withrespect to Block Copolymer B₁ not added with any basic compound.

The results are collectively shown in Table 3.

COMPARATIVE EXAMPLE 7

Still further pellet samples were prepared in a similar manner toExample 13 except for the addition of NaCl and calcium stearate asadditives, respectively. The respective melt viscosities of each pelletsample and their ratios were determined (Experiment Nos. 7-1 and 7-2).

A still further pellet sample was prepared in a similar manner toExample 13 except that a composition obtained by adding 0.5 part byweight of calcium hydroxide to 100 parts by weight of poly(arylenethioether-ketone) homopolymer (PTK-1) and the cylinder temperature waschanged to 370° C. The respective melt viscosities and their ratios weredetermined (Experiment No. 7-3).

A still further pellet sample was prepared in a similar manner toExample 13 except for the use of a composition obtained by adding 0.5part by weight of calcium hydroxide to 100 parts by weight ofpoly(paraphenylene thioether) which was PATE containing no ketone groupsin the molecule (product of Kureha Chemical Industry Co., Ltd.; inherentviscosity, η_(inh) : 0.48 as measured at 208° C. and at a concentrationof 0.4 g/dl in 1-chloronaphthalene). Its η*₅ and η*₃₀ and η*₃₀ /η*₅ werethen determined (Experiment No. 7-4).

The results are collectively shown in Table 3.

Incidentally, PTK-1 employed in Experiment No. 7-3 was synthesized inthe following manner.

A titanium-lined reactor was charged with 90 moles of DCBP, 90 moles ofhydrated sodium sulfide (water content: 53.6 wt. %) and 90 kg of NMP(water content/NMP=5 mol/kg). After the reactor being purged withnitrogen gas, the contents were heated from room temperature to 240° C.over 1.5 hours and were then maintained at 240° C. for 2 hours to reactthem. Thereafter, to effect a stabilization treatment in a final stageof the reaction, 4.5 moles of DCBP, 18 kg of NMP and 90 moles of waterwere added, followed by a reaction at 240° C. for further 1 hour.

The reactor was cooled and the reaction mixture in the form of a slurrywas taken out of the reactor. The slurry was poured into about 200 l ofacetone to have the resultant polymer precipitated. Thethus-precipitated polymer was collected by filtration and washed twicewith acetone and additionally twice with water. Acetone and water wereremoved to obtain the polymer in a wet form.

The wet polymer thus obtained was dried at 100° C. for 12 hours underreduced pressure to obtain PTK-1.

The melting point of that PTK-1 (powder) was 360° C.

Further, the reduced viscosity η_(red) of PTK-1 as measured at 25° C. bya Ubbelohde's viscometer after dissolving the PTK-1 at a concentrationof 0.5 g/dl in 98% sulfuric acid was 0.63 dl/g.

                                      TABLE 3                                     __________________________________________________________________________                    Example 13                  Comparative Example 7             Experiment No.  13-1 13-2 13-3 13-4                                                                              13-5                                                                              13-6 7-1 7-2  7-3  7-4                 __________________________________________________________________________    Block copolymer, B.sub.1 (wt. parts)                                                          100  100  100  100 100 100  100 100  PTK-1.sup.1)                                                                       PATE.sup.2)                                                              100  100                 Stabilizer      Ca(OH).sub.2                                                                       Ca(OH).sub.2                                                                       Ca(OH).sub.2                                                                       Li.sub.2 CO.sub.3                                                                 CaO Ba(OH).sub.2                                                                       NaCl                                                                              Calcium                                                                            Ca(OH).sub.2                                                                       Ca(OH).sub.2        (wt. parts)     0    0.2  0.5  0.5 0.5 1.0  0.5 stearate                                                                           0.5  0.5                                                                 0.5                           Melt stability                                                                (350° C., 1200 sec.sup.-1)                                             η*.sub.30 /η*.sub.5                                                                   1.3  0.9  0.9  1.0 0.9 1.0  1.3 --.sup.3)                                                                          1.0.sup.4)                                                                         0.4                 η*.sub.60 /η*.sub.5                                                                   3.5  1.1  1.0  1.1 1.2 1.1  3.9 --.sup.3)                                                                          1.1.sup.4)                                                                         --                  __________________________________________________________________________     .sup.1) Poly(arylene thioetherketone) (reduced viscosity η.sub.red :      0.63 dl/g as measured at 25° C. and a polymer concentration of 0.5     g/dl in 98% concentrated sulfuric acid.)                                      .sup.2) Poly(pphenylene thioether) (product of Kureha Chemical Industry       Co., Ltd.; inherent viscosity η.sub.inh : 0.48 as measured at             208° C. at a polymer concentration of 0.4 g/dl in                      1chloronaphthalene).                                                          .sup.3) Measurement was discontinued due to violent foaming.                  .sup.4) Measured at 370° C. and 1200 sec.                         

As is apparent from Experiment No. 13-1 of Table 3, the block copolymeraccording to this invention exhibited good melt stability without anstabilizer because its melt viscosity was substantially unchanged evenwhen it was maintained for 30 minutes at 350° C. which is close to themelt processing temperature.

It is envisaged from Experiment Nos. 13-2 to 13-6 that the meltstability of the block copolymer can be improved further by the additionof a basic compound and the melt viscosity remains substantiallyunchanged even when maintained at 350° C. for 60 minutes. In addition,the deposition of decomposition products to the barrel of Capirographwas reduced.

On the other hand, it is understood from Experiment Nos. 7-1 and 7-2that the addition of NaCl or calcium stearate does not bring about meltstabilization effect or induces foaming to conversely impair the meltstability.

Although melt stabilization effect is observed from the addition ofcalcium hydroxide in the case of PTK homopolymer (Experiment No. 7-3),the melt stability was conversely deteriorated in the case of PATEhomopolymer because η*₃₀ /η*₅ of its pellets extruded without additionof any basic compound was 0.7 while η*₃₀ /η*₅ of its pellets extrudedafter addition of calcium hydroxide was 0.4 (Experiment No. 7-4).

EXAMPLE 14 Melt Stabilization (2) of Block Copolymers by the Addition ofStabilizer

Employed as block copolymers were Block Copolymer B₁ synthesized inExample 1 and Block Copolymer B₁₁ synthesized in Example 11. Thosepolymers were added with the basic compound or the basic compound andantioxidants shown in Table 4, and pellet samples were preparedtherefrom in a similar manner to Example 13. Their melt stabilities werethen investigated. In order to conduct evaluation by enlargingdifferences in melt stability among the samples, values of meltviscosity as measured at 370° C. and a shear rate of 1200 sec⁻¹ wereused in addition to the evaluation conditions of 350° C. and the shearrate of 1200 sec⁻¹.

The measurement results are given in Table 4.

As is clearly envisaged from Table 4, the melt stability of each blockcopolymer of this invention has been improved by the addition of thebasic compound either alone or in combination with the antioxidant.Further, the deposition of decomposition products on the barrel ofCapirograph was also reduced substantially.

Incidentally, the individual antioxidant used in Table 4 are as follows:

Phosphorus Compounds

(a) PEP 36: product of Adeka Argus Chemical Co., Ltd.;bis-(2,6-di-tert-butyl-4-methylphenyl)pentaerythritoldiphosphite.

(b) IRGAFOS 168: product of Ciba-Geigy AG;tris(2,4-di-tert-butylphenyl)phosphite.

(c) SANDSTAB P-EPQ: product of Sandoz AG; phosphorusacid[1,1-biphenyl-4,4'-diyl-bistetrakis[2,4-bis(1,1-dimethylethyl)phenyl]ester].

(d) WESTON 618: product of Borg-Warner Corporation; distearylpentaerythritol diphosphite.

Hindered Phenol Compound

(e) AO-220: product of Adeka Argus Chemical Co., Ltd.; a compoundanalogous to1,3,5-trimethyl-2,4,6-tris-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene.

Hindered Amine Compound

(f) CHIMASSORB 944 LD: product of Ciba-Geigy AG;poly[[6-(1,1,3,3-tetramethylbutyl)imino-1,3,5-triazine-2,4-diil][(2,2,6,6-tetramethyl-4-piperidyl)imino]hexamethylene[(2,2,6,6-tetramethyl-4-piperidyl)imino]].

                                      TABLE 4                                     __________________________________________________________________________    Experiment No.                                                                              14-1  14-2  14-3 14-4 14-5  14-6                                __________________________________________________________________________    Block copolymer                                                                             B.sub.1                                                                             B.sub.1                                                                             B.sub.1                                                                            B.sub.1                                                                            B.sub.1                                                                             B.sub.1                             (wt. parts)   100   100   100  100  100   100                                 Stabilizer - Basic compound                                                                 Ca(OH).sub.2                                                                        Ca(OH).sub.2                                                                        Ca(OH).sub.2                                                                       Ca(OH).sub.2                                                                       Ca(OH).sub.2                                                                        Ca(OH).sub.2                        (wt. parts)   0     0.5   1.0  1.5  1.0   1.0                                 Antioxidant   --    --    --   --   Phosphorus                                                                          Phosphorus                                                              comp'd                                                                              comp'd                                                                  (a)   (b)                                 (wt. parts)                         0.5   0.5                                 Melt stability                                                                (370° C., 1200 sec.sup.-1)                                             η*.sub.30 /η*.sub.5                                                                 25.4  0.90  1.04 0.93 1.08  0.84                                η*.sub.60 /η*.sub.5                                                                 --    1.70  1.80 1.50 1.08  1.07                                (350° C., 1200 sec.sup.-1)                                             η*.sub.30 /η*.sub.5                                                                 1.2   0.9   1.01 0.98 1.01  --                                  η*.sub.60 /η*.sub.5                                                                 3.4   0.9   1.02 1.04 1.03  --                                  __________________________________________________________________________    Experiment No.                                                                              14-7  14-8  14-9 14-10                                                                              14-11 14-12                               __________________________________________________________________________    Block copolymer                                                                             B.sub.1                                                                             B.sub.1                                                                             B.sub.1                                                                            B.sub.1                                                                            B.sub.11                                                                            B.sub.11                            (wt. parts)   100   100   100  100  100   100                                 Stabilizer - Basic compound                                                                 Ca(OH).sub.2                                                                        Ca(OH).sub.2                                                                        Ca(OH).sub.2                                                                       Ca(OH).sub.2                                                                       Ca(OH).sub.2                                                                        Ca(OH).sub.2                        (wt. parts)   1.0   1.0   1.0  1.0  1.0   1.0                                 Antioxidant   Phosphorus                                                                          Phosphorus                                                                          Phenol                                                                             Amine                                                                              Phosphorus                                                                          Phosphorus                                        comp'd                                                                              comp'd                                                                              comp'd                                                                             comp'd                                                                             comp'd                                                                              comp'd                                            (c)   (d)   (e)  (f)  (a)   (b)                                 (wt. parts)   0.5   0.5   0.5  0.5  0.5   0.5                                 Melt stability                                                                (370° C., 1200 sec.sup.-1)                                             η*.sub.30 /η*.sub.5                                                                 0.86  0.88  0.96 0.80 0.99  1.01                                η*.sub.60 /η*.sub.5                                                                 1.07  1.06  1.25 0.85 1.03  1.02                                (350° C., 1200 sec.sup.-1)                                             η*.sub.30 /η*.sub.5                                                                 --    --    --   --   --    --                                  η*.sub.60 /η*.sub.5                                                                 --    --    --   --   --    --                                  __________________________________________________________________________

EXAMPLE 15 Molding Experiment (1) Using Block Copolymer

Using Block Copolymer B₁ synthesized in Example 1, pellet samples wereprepared in accordance with the compositions shown in Table 5,respectively.

Each of those pellet samples was charged into an injection moldingmachine under a nitrogen gas stream, and was then injection-molded at acylinder temperature of 350° C., a mold temperature of 160° C., aninjection holding pressure of 1000 kg/cm² and an injection cycle ofabout 40 seconds so that injection-molded products were obtained.

By the addition of the stabilizers, the long run property at the time ofmolding was improved so that the deposition of decomposition products tothe molding machine was reduced.

The compositions and the physical properties and solvent resistance ofthe injection-molded products are summarized in Table 5.

                  TABLE 5                                                         ______________________________________                                                      Example 15                                                      Experiment No.                                                                            ASTM    15-1     15-2   15-3                                      ______________________________________                                        Block copolymer B.sub.1                                                                           100      100    100                                       (wt. parts)                                                                   Stabilizer                                                                    (wt. parts)                                                                   Basic compound      0        Ca(OH).sub.2                                                                         Ca(OH).sub.2                                                           0.5    0.5                                       Antioxidant         0        0      Phosphorus.sup.1)                                                             compound                                                                      0.5                                       Flexural strength                                                                         D790    8        7      8                                         (23° C.) [kg/mm.sup.2 ]                                                Flexural modulus                                                                          D790    310      310    300                                       (23° C.) [kg/mm.sup.2 ]                                                Heat distortion                                                                           D648    140      140    140                                       temperature                                                                   (°C.) [18.6 kg/cm.sup.2 ]                                              Solvent resistance                                                            α-Chloro-     Insoluble                                                                              Insoluble                                                                            Insoluble                                 naphthalene.sup.2)                                                            NMP.sup.3)          Insoluble                                                                              Insoluble                                                                            Insoluble                                 98% conc. H.sub.2 SO.sub.4.sup.4)                                                                 Insoluble                                                                              Insoluble                                                                            Insoluble                                 ______________________________________                                         .sup.1) "PEP 36"; product of Adeka Argus Chemical Co., Ltd.                   .sup.2) Immersed at 225° C. for 5 minutes.                             .sup.3) Immersed at 200° C. for 5 minutes.                             .sup.4) Immersed at room temperature for 30 minutes.                     

EXAMPLE 16 Extrusion Experiment (2) Using Block Copolymer

Using Block Copolymer B₁ synthesized in Example 1, pellet samples wereprepared in accordance with the compositions shown in Table 6,respectively.

Each of those pellet samples was charged into a single-screw extruderhaving a cylinder diameter of 35 mm and equipped with a small T-die, andwas then melt-extruded at a cylinder temperature of 350° C. Theextrudate was quenched by quenching rolls to prepare an unstretched filmhaving an average thickness of 150 μm.

The unstretched films thus obtained were individually cut into pieces of10 mm wide and 20 mm long. Their strengths and elongations were measuredby using TENSILON (model: "RTM-100"; manufactured by Toyo-Baldwin Co.,Ltd.). The measurements were conducted at 23° C. and a deformation rateof 10 mm/min (50%/min).

By the addition of the stabilizers, the long run property at the time ofextrusion was improved so that the deposition of decomposition productsto the extruder and cooling rolls was reduced.

Incidentally, the solder resistance (10 sec) of each sample wasexpressed by the highest solder temperature at which changes in externalappearance, such as swelling and wrinkling, were not developed when thesample was annealed at 200° C. for 2 hours and then immersed for 10seconds in a solder bath. The temperature of the solder bath wascontrolled in 5° C. increments.

The results are summarized in Table 6.

                  TABLE 6                                                         ______________________________________                                                       Example 16                                                     Experiment No.                                                                             ASTM    16-1     16-2   16-3                                     ______________________________________                                        Block copolymer B.sub.1                                                                            100      100    100                                      (wt. parts)                                                                   Stabilizer (wt. parts)                                                        Basic compound       0        Ca(OH).sub.2                                                                         Ca(OH).sub.2                                                           0.5    0.3                                      Antioxidant          0        0      Phenol.sup.1)                                                                 compound                                                                      0.2                                      Density.sup.2) (25° C.)                                                [g/cm.sup.3 ]                                                                 Amorphous sheet      1.30     1.30   1.30                                     Crystallized product.sup.3)                                                                        1.36     1.36   1.36                                     Strength and                                                                  elongation                                                                    characteristics (23° C.)                                               Tensile strength at                                                                        D638    6        6      6                                        yield point [kg/mm.sup.2 ]                                                    Tensile strength at                                                                        D638    4        5      5                                        break point [kg/mm.sup.2 ]                                                    Tensile elongation                                                                         D638    310      360    350                                      at break (%)                                                                  Tensile modulus                                                                            D638    220      225    220                                      [kg/mm.sup.2 ]                                                                Solder heat resistance                                                                             >280     >280   >280                                     [°C.]                                                                  (immersed for 10                                                              seconds in solder bath)                                                       Solvent resistance                                                            α-Chloronaphthalene.sup.4)                                                                   Insoluble                                                                              Insoluble                                                                            Insoluble                                NMP.sup.5)           Insoluble                                                                              Insoluble                                                                            Insoluble                                98% conc. H.sub.2 SO.sub.4.sup.6)                                                                  Insoluble                                                                              Insoluble                                                                            Insoluble                                ______________________________________                                         .sup.1) "AO220", product of Adeka Argus Chemical Co., Ltd.                    .sup.2) By lithium bromide/water system gradient tube density                 determination.                                                                .sup.3) Annealed at 280° C. for 30 minutes.                            .sup.4) Immersed at 225° C. for 5 minutes.                             .sup.5) Immersed at 200° C. for 5 minutes.                             .sup.6) Immersed at room temperature for 30 minutes.                     

We claim:
 1. A process for the production of a poly(arylene thioether)block copolymer comprising (A) at least one poly(arylenethioether-ketone) block and (B) at least one poly(arylene thioether)block, which comprises at least the following three steps:i) heating inthe presence of water an organic amide solvent containing adihalogenated aromatic compound, which consists principally of adihalobenzene, and an alkali metal sulfide, whereby a first reactionmixture containing a poly(arylene thioether) prepolymer havingpredominant recurring units of the formula ##STR27## and reactiveterminal groups is formed, ii) heating in the presence of water anorganic amide solvent containing a dihalogenated aromatic compound,which consists principally of at least one dihalobenzophenone selectedfrom 4,4'-dichlorobenzophenone and 4,4'-dibromobenzophenone, an alkalimetal sulfide, whereby a second reaction mixture containing apoly(arylene thioether-ketone) prepolymer having predominant recurringunits of the formula ##STR28## wherein the --CO-- and --S-- are in thepara position to each other and reactive terminal groups is formed, andiii) mixing and reacting the first reaction mixture, which has beenobtained in the first step i) and contains the poly(arylene thioether)prepolymer, with the second reaction mixture obtained in the second stepii) and containing the poly(arylene thioetherketone) prepolymer;saidfirst through third steps i)-iii) being conducted under the followingconditions (a)-(g): (a) in the first step i), the ratio of the watercontent to the amount of the charged organic amide solvent being 0.2-5(mol/kg), the ratio of the amount of the charged dihalogenated aromaticcompound to the amount of the charged alkali metal sulfide being0.8-1.05 (mol/mol), and the polymerization being conducted until theaverage polymerization degree of the poly(arylene thioether) prepolymerbecomes at least 10, (b) in the second step, the ratio of the watercontent to the amount of the charged organic amide solvent beingcontrolled within a range of 2.5-15 (mol/kg) and the reaction beingconducted within a temperature range of 60°-300° C. with the provisothat the reaction time at 210° C. and higher is not longer than 10hours, (c) in the third step, the ratio of the water content to theamount of the charged organic amide solvent being controlled within arange of 2.5-15 (mol/kg) (d) in the third step, the ratio of the totalamount of the charged dihalogenated aromatic compound, said total amountbeing the amount of the whole dihalogenated aromatic compounds includingthe dihalobenzene and the dihalobenzophenone to the total amount of thecharged alkali metal sulfide, said latter total amount being the totalamount of the alkali metal sulfide charged in the first step i) and thatcharged in the second step ii), being controlled within a range of0.95-1.2 (mol/mol), (e) the ratio of the whole poly(arylene thioether)prepolymer to the whole poly(arylene thioether-ketone) prepolymer beingcontrolled at 0.05-5 by weight, (f) the reaction of the third step iii)being conducted within a temperature range of 150°-300° C. with theproviso that the reaction time at 210° C. and higher is not longer than10 hours, and (g) in the third step iii), the reaction is conducteduntil the melt viscosity of the resulting block copolymer becomes2-100,000 poises as measured at 350° C. and a shear rate of 1,200/sec.2. The process as claimed in claim 1, wherein the poly(arylenethioether) prepolymer has predominant recurring units of the formula##STR29##
 3. The process as claimed in claim 1, wherein in each of thesteps i) through iii), the reaction is conducted in a reactor at least aportion of which, said portion being brought into contact with thereaction mixture, is made of a corrosion-resistant material.
 4. Theprocess as claimed in claim 3, wherein the corrosion-resistant materialis a titanium material.
 5. The process as claimed in claim 1, whereinthe organic amide solvent is at least one pyrrolidone selected fromN-methylpyrrolidone and N-ethylpyrrolidone.
 6. The process as claimed inclaim 1, wherein upon obtaining the poly(arylene thioether) blockcopolymer, at least 50 wt. % of the resulting block copolymer is in theform of granules recoverable on a sieve having an opening size of 75 μm.